Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace blower, using my usual piece of aquarium hose stuck in my ear g, and I wondered if there might be a market for an advanced kind of mechanic's stethoscope -- something that ought to be a piece of cake for someone like you.

Maybe something like this is on the market. If so, forget it. If not, consider this:

I had two noises, from different sources, and the interference between them made it all but impossible to find the origins of the noises. One was some mechanical interference between the centrifugal fan and its housing, at one end of the armature shaft; the other was vibration resulting from stickiness in the centrifugal throw-out switch (a fail-safe switch that prevents the gas valve from opening), at the other end of the shaft. I finally took the whole thing apart and found both problems, but it wasn't easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap, battery-powered amplifier, with a mike and a headphone jack, that contained a couple of active, adjustable audio filters, one high-pass and another low-pass. Made a notching filter or bandpass filter to make it slick.

I don't play with engines much these days, but I can recall times when such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out for patents.

--
Ed Huntress

wrote in message
...
Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and
I wondered if there might be a market for an advanced kind of
mechanic's stethoscope -- something that ought to be a piece of cake
for someone like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the
other end of the shaft. I finally took the whole thing apart and found
both problems, but it wasn't easy to find them when the motor wasn't
running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one high-pass
and another low-pass. Made a notching filter or bandpass filter to
make it slick.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine
noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

--
Ed Huntress

====================

That's how a knock sensor works. It selectively amplifies the
resonance frequency of the engine block and retards the spark if the
level is above a threshhold, or allows it to slowly advance if the
level is below it. Thus it constantly adapts spark timing to the
fuel's octane and the power demand.

I first saw them on the mid-70's Buick turbo V6.

-jsw

wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace blower,
using my usual piece of aquarium hose stuck in my ear g, and I wondered
if there might be a market for an advanced kind of mechanic's stethoscope
-- something that ought to be a piece of cake for someone like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:
There definitely are electronic stethoscopes on the market. You can buy
them at auto parts stores. They have some sort of vibration mike on the end
of a long rod, so you can poke the rod down into the works where engine
accessory bearings are.

Jon

On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace blower,
using my usual piece of aquarium hose stuck in my ear g, and I wondered
if there might be a market for an advanced kind of mechanic's stethoscope
-- something that ought to be a piece of cake for someone like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:
There definitely are electronic stethoscopes on the market. You can buy
them at auto parts stores. They have some sort of vibration mike on the end
of a long rod, so you can poke the rod down into the works where engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make them a lot more useful in something noisy, like an IC engine. I made some audio filters for use in ham radio a couple of decades ago, and they were great when I was playing with direct-conversion receivers, which let a lot of noise through.

--
Ed Huntress
KC2NZT

wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:
There definitely are electronic stethoscopes on the market. You can
buy
them at auto parts stores. They have some sort of vibration mike on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I made
some audio filters for use in ham radio a couple of decades ago, and
they were great when I was playing with direct-conversion receivers,
which let a lot of noise through.

--
Ed Huntress
KC2NZT

============
How about a "waterfall" or spectrogram display on a smart phone,
showing both frequency peaks and repeating pulses and how they relate
to engine RPM?
http://www.epanorama.net/newepa/2013...gnal-analyzer/

On Friday, April 7, 2017 at 4:01:09 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:
There definitely are electronic stethoscopes on the market. You can
buy
them at auto parts stores. They have some sort of vibration mike on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I made
some audio filters for use in ham radio a couple of decades ago, and
they were great when I was playing with direct-conversion receivers,
which let a lot of noise through.

--
Ed Huntress
KC2NZT

============
How about a "waterfall" or spectrogram display on a smart phone,
showing both frequency peaks and repeating pulses and how they relate
to engine RPM?
http://www.epanorama.net/newepa/2013...gnal-analyzer/

Er...ah...well, yeah, I guess. Then you have to teach users how to read the displays. g

--
Ed Huntress

On Fri, 7 Apr 2017 08:51:21 -0700 (PDT), wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace blower, using my usual piece of aquarium hose stuck in my ear g, and I wondered if there might be a market for an advanced kind of mechanic's stethoscope -- something that ought to be a piece of cake for someone like you.

Maybe something like this is on the market. If so, forget it. If not, consider this:

I had two noises, from different sources, and the interference between them made it all but impossible to find the origins of the noises. One was some mechanical interference between the centrifugal fan and its housing, at one end of the armature shaft; the other was vibration resulting from stickiness in the centrifugal throw-out switch (a fail-safe switch that prevents the gas valve from opening), at the other end of the shaft. I finally took the whole thing apart and found both problems, but it wasn't easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap, battery-powered amplifier, with a mike and a headphone jack, that contained a couple of active, adjustable audio filters, one high-pass and another low-pass. Made a notching filter or bandpass filter to make it slick.

I don't play with engines much these days, but I can recall times when such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out for patents.
They have been on the market for decades.. Steelman Engine-ear and
Chassis-Ear, along with 8-Mile-Lake and SKF TMST3 are pretty common in
the industry. The Chassis-Ear has several remote sensors you can
install in multiple places and switch between them on the run.

On Fri, 7 Apr 2017 16:02:53 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:
There definitely are electronic stethoscopes on the market. You can
buy
them at auto parts stores. They have some sort of vibration mike on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I made
some audio filters for use in ham radio a couple of decades ago, and
they were great when I was playing with direct-conversion receivers,
which let a lot of noise through.
Cardiologists stethophones have had ambient noise reduction for a
few years already. It makes hearing heart noises a lot easier. They
are digital devices with DSP circuitry.

On Fri, 7 Apr 2017 13:42:24 -0700 (PDT), wrote:

On Friday, April 7, 2017 at 4:01:09 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:
There definitely are electronic stethoscopes on the market. You can
buy
them at auto parts stores. They have some sort of vibration mike on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I made
some audio filters for use in ham radio a couple of decades ago, and
they were great when I was playing with direct-conversion receivers,
which let a lot of noise through.

--
Ed Huntress
KC2NZT

============
How about a "waterfall" or spectrogram display on a smart phone,
showing both frequency peaks and repeating pulses and how they relate
to engine RPM?
http://www.epanorama.net/newepa/2013...gnal-analyzer/

Er...ah...well, yeah, I guess. Then you have to teach users how to read the displays. g
Look what $150 can buy - for the medical field --
http://www.ebay.com/itm/Intelligent-...-/172577642484

On Fri, 7 Apr 2017 13:42:24 -0700 (PDT), wrote:

On Friday, April 7, 2017 at 4:01:09 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:
There definitely are electronic stethoscopes on the market. You can
buy
them at auto parts stores. They have some sort of vibration mike on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I made
some audio filters for use in ham radio a couple of decades ago, and
they were great when I was playing with direct-conversion receivers,
which let a lot of noise through.

--
Ed Huntress
KC2NZT

============
How about a "waterfall" or spectrogram display on a smart phone,
showing both frequency peaks and repeating pulses and how they relate
to engine RPM?
http://www.epanorama.net/newepa/2013...gnal-analyzer/

Er...ah...well, yeah, I guess. Then you have to teach users how to read the displays. g
and what is availble for "medical" use for under $100

http://www.ebay.com/itm/Electronic-S...-/272613605152

wrote in message
...
On Friday, April 7, 2017 at 4:01:09 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 3:13:24 PM UTC-4, Jon Elson wrote:
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my
furnace
blower,
using my usual piece of aquarium hose stuck in my ear g, and
I
wondered
if there might be a market for an advanced kind of mechanic's
stethoscope
-- something that ought to be a piece of cake for someone like
you.

Maybe something like this is on the market. If so, forget it.
If
not,
consider this:
There definitely are electronic stethoscopes on the market. You
can
buy
them at auto parts stores. They have some sort of vibration mike
on
the end
of a long rod, so you can poke the rod down into the works where
engine
accessory bearings are.

Jon

Yeah, I've seen those, but I thought the active filters would make
them a lot more useful in something noisy, like an IC engine. I
made
some audio filters for use in ham radio a couple of decades ago,
and
they were great when I was playing with direct-conversion
receivers,
which let a lot of noise through.

--
Ed Huntress
KC2NZT

============
How about a "waterfall" or spectrogram display on a smart phone,
showing both frequency peaks and repeating pulses and how they
relate
to engine RPM?
http://www.epanorama.net/newepa/2013...gnal-analyzer/

Er...ah...well, yeah, I guess. Then you have to teach users how to
read the displays. g

--
Ed Huntress

Users already have to learn how to interpret the sounds. This could
show if the sound is related to the speed of the crankshaft, or of the
camshaft, alternator, etc.

The upper and lower filters could isolate individual sounds which they
both see and hear. Without the display they don't know what the
filters are doing.
-jsw

On Friday, April 7, 2017 at 5:30:08 PM UTC-4, Clare wrote:
On Fri, 7 Apr 2017 08:51:21 -0700 (PDT), wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace blower, using my usual piece of aquarium hose stuck in my ear g, and I wondered if there might be a market for an advanced kind of mechanic's stethoscope -- something that ought to be a piece of cake for someone like you.

Maybe something like this is on the market. If so, forget it. If not, consider this:

I had two noises, from different sources, and the interference between them made it all but impossible to find the origins of the noises. One was some mechanical interference between the centrifugal fan and its housing, at one end of the armature shaft; the other was vibration resulting from stickiness in the centrifugal throw-out switch (a fail-safe switch that prevents the gas valve from opening), at the other end of the shaft. I finally took the whole thing apart and found both problems, but it wasn't easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap, battery-powered amplifier, with a mike and a headphone jack, that contained a couple of active, adjustable audio filters, one high-pass and another low-pass. Made a notching filter or bandpass filter to make it slick.

I don't play with engines much these days, but I can recall times when such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out for patents.
They have been on the market for decades.. Steelman Engine-ear and
Chassis-Ear, along with 8-Mile-Lake and SKF TMST3 are pretty common in
the industry. The Chassis-Ear has several remote sensors you can
install in multiple places and switch between them on the run.

Too little, too late, once again. g

--
Ed Huntress

wrote in message
...
On Friday, April 7, 2017 at 5:30:08 PM UTC-4, Clare wrote:
On Fri, 7 Apr 2017 08:51:21 -0700 (PDT),
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g,
and I wondered if there might be a market for an advanced kind of
mechanic's stethoscope -- something that ought to be a piece of
cake for someone like you.

Maybe something like this is on the market. If so, forget it. If
not, consider this:

I had two noises, from different sources, and the interference
between them made it all but impossible to find the origins of the
noises. One was some mechanical interference between the
centrifugal fan and its housing, at one end of the armature shaft;
the other was vibration resulting from stickiness in the
centrifugal throw-out switch (a fail-safe switch that prevents the
gas valve from opening), at the other end of the shaft. I finally
took the whole thing apart and found both problems, but it wasn't
easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one
high-pass and another low-pass. Made a notching filter or bandpass
filter to make it slick.

I don't play with engines much these days, but I can recall times
when such a device would have made quick work of tracking down
engine noises.

There it is. If you make it and sell it, the idea is yours. Watch
out for patents.
They have been on the market for decades.. Steelman Engine-ear and
Chassis-Ear, along with 8-Mile-Lake and SKF TMST3 are pretty common
in
the industry. The Chassis-Ear has several remote sensors you can
install in multiple places and switch between them on the run.

Too little, too late, once again. g
Ed Huntress

=====================
Don't feel bad, I was the assistant to brilliant engineers working at
the leading edge yet I never invented anything commercially valuable.
All my contributions were kick-yourself-for-missing-it simple.
-jsw

On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 5:30:08 PM UTC-4, Clare wrote:
On Fri, 7 Apr 2017 08:51:21 -0700 (PDT),
wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g,
and I wondered if there might be a market for an advanced kind of
mechanic's stethoscope -- something that ought to be a piece of
cake for someone like you.

Maybe something like this is on the market. If so, forget it. If
not, consider this:

I had two noises, from different sources, and the interference
between them made it all but impossible to find the origins of the
noises. One was some mechanical interference between the
centrifugal fan and its housing, at one end of the armature shaft;
the other was vibration resulting from stickiness in the
centrifugal throw-out switch (a fail-safe switch that prevents the
gas valve from opening), at the other end of the shaft. I finally
took the whole thing apart and found both problems, but it wasn't
easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one
high-pass and another low-pass. Made a notching filter or bandpass
filter to make it slick.

I don't play with engines much these days, but I can recall times
when such a device would have made quick work of tracking down
engine noises.

There it is. If you make it and sell it, the idea is yours. Watch
out for patents.
They have been on the market for decades.. Steelman Engine-ear and
Chassis-Ear, along with 8-Mile-Lake and SKF TMST3 are pretty common
in
the industry. The Chassis-Ear has several remote sensors you can
install in multiple places and switch between them on the run.

Too little, too late, once again. g
Ed Huntress

=====================
Don't feel bad, I was the assistant to brilliant engineers working at
the leading edge yet I never invented anything commercially valuable.
All my contributions were kick-yourself-for-missing-it simple.
-jsw

For my part, I always invent things that have been in use for 30 or more years. g

My uncle had the knack, but he never patented anything. He did get Ocean City Reels (now a part of Penn Reels) to pay him a bunch of money for his star-drag fishing reel, back in the 1920s. I still have the duplicate; he made two of them, all silver-brazed from Monel. I should upload a photo of it some time.

--
Ed Huntress

On 2017-04-07, wrote:
Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and I
wondered if there might be a market for an advanced kind of mechanic's
stethoscope -- something that ought to be a piece of cake for someone
like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the other
end of the shaft. I finally took the whole thing apart and found both
problems, but it wasn't easy to find them when the motor wasn't running.

Hmm ... makes me think of a mechanic's stethoscope which I used
to have which might have helped here. Instead of having the usual
stethoscope "Y" to direct one sensor to two ears, it had a separate hose
from each earpiece, which went to a round plastic pillbox with a hole
and nipple in the center of one side, and a threaded nipple in the
center of the other side into which a length of 1/8" brass rod screwed.
At the end of the rods were corks for contact to the device.

This gave a stereo signal, so you could tell which sensor was
louder and thus which was closer to the source of the noise.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one high-pass
and another low-pass. Made a notching filter or bandpass filter to make
it slick.

Instead of a microphone, use an old phono cartridge with a brass
whisker where the needle normally was held. (Ceramic or Crystal
cartridge -- not the fancier stereo cartridges of higher quality and
lower stylus force which came later.) Astatic was the brand of one of
these types. I wonder if you can still find them on eBay?

Nope! Nothing old enough. What you need should be mono, with a
single pair of terminals, and a thumbscrew in the front to lock the new
stylus (or the brass rod) into.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

It sounds interesting -- and more so if you can do stereo
pickups with old phono cartridges. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Friday, April 7, 2017 at 8:19:54 PM UTC-4, DoN. Nichols wrote:
On 2017-04-07, wrote:
Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and I
wondered if there might be a market for an advanced kind of mechanic's
stethoscope -- something that ought to be a piece of cake for someone
like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the other
end of the shaft. I finally took the whole thing apart and found both
problems, but it wasn't easy to find them when the motor wasn't running.

Hmm ... makes me think of a mechanic's stethoscope which I used
to have which might have helped here. Instead of having the usual
stethoscope "Y" to direct one sensor to two ears, it had a separate hose
from each earpiece, which went to a round plastic pillbox with a hole
and nipple in the center of one side, and a threaded nipple in the
center of the other side into which a length of 1/8" brass rod screwed.
At the end of the rods were corks for contact to the device.

This gave a stereo signal, so you could tell which sensor was
louder and thus which was closer to the source of the noise.

That sounds nice and simple. I really like simple. d8-)


So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one high-pass
and another low-pass. Made a notching filter or bandpass filter to make
it slick.

Instead of a microphone, use an old phono cartridge with a brass
whisker where the needle normally was held. (Ceramic or Crystal
cartridge -- not the fancier stereo cartridges of higher quality and
lower stylus force which came later.) Astatic was the brand of one of
these types. I wonder if you can still find them on eBay?

Nope! Nothing old enough. What you need should be mono, with a
single pair of terminals, and a thumbscrew in the front to lock the new
stylus (or the brass rod) into.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

It sounds interesting -- and more so if you can do stereo
pickups with old phono cartridges. :-)

Enjoy,
DoN.

I think I have a couple of those old phono cartridges in the attic somewhere. With my pack-rat tendencies, I usually save the old one when I put a new thingy in.

What I *don't* have is much ambition to pursue things like that. If it isn't fishing. photography, or boat gear, I try to avoid it. Time is becoming precious.

But thanks for the thoughts. I really like the stereo stethoscope idea.

--
Ed Huntress


--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which I
had to tell him was patented in 1796.
-jsw

On Friday, April 7, 2017 at 9:19:10 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which I
had to tell him was patented in 1796.
-jsw

Wow. Unless it was a life-saving antibiotic, at least the patent has run out. g

--
Ed Huntress

wrote in message
...
On Friday, April 7, 2017 at 9:19:10 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which
I
had to tell him was patented in 1796.
-jsw

Wow. Unless it was a life-saving antibiotic, at least the patent has
run out. g

--
Ed Huntress

Vaccination is that old, but fortunately we don't suffer the other
medical procedures of that era.

On Fri, 7 Apr 2017 22:23:38 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Friday, April 7, 2017 at 9:19:10 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which
I
had to tell him was patented in 1796.
-jsw

Wow. Unless it was a life-saving antibiotic, at least the patent has
run out. g

--
Ed Huntress

Vaccination is that old, but fortunately we don't suffer the other
medical procedures of that era.

True.

But we all still wish the doctors weren't so barbaric nowadays. I
can't wait for the medical community to discover and conquer PAIN.

--
Newman's First Law:
It is useless to put on your brakes when you're upside down.
--Paul Newman

On Friday, April 7, 2017 at 11:19:37 PM UTC-4, Larry Jaques wrote:
On Fri, 7 Apr 2017 22:23:38 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Friday, April 7, 2017 at 9:19:10 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which
I
had to tell him was patented in 1796.
-jsw

Wow. Unless it was a life-saving antibiotic, at least the patent has
run out. g

--
Ed Huntress

Vaccination is that old, but fortunately we don't suffer the other
medical procedures of that era.

True.

But we all still wish the doctors weren't so barbaric nowadays. I
can't wait for the medical community to discover and conquer PAIN.


Pfizer has a patent on it. The doctors won't be able to touch it for at least 28 years, at which time Pfizer will come up with a metabolite of pain and patent it for another 28.

(Old medical editors' joke...)

--
Ed Huntress




--
Newman's First Law:
It is useless to put on your brakes when you're upside down.
--Paul Newman

Larry Jaques wrote:
On Fri, 7 Apr 2017 22:23:38 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Friday, April 7, 2017 at 9:19:10 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Friday, April 7, 2017 at 6:43:25 PM UTC-4, Jim Wilkins wrote:

For my part, I always invent things that have been in use for 30 or
more years. g
--
Ed Huntress

========================
A poster in an alternate energy group proposed a bright idea which
I
had to tell him was patented in 1796.
-jsw

Wow. Unless it was a life-saving antibiotic, at least the patent has
run out. g

--
Ed Huntress

Vaccination is that old, but fortunately we don't suffer the other
medical procedures of that era.

True.

But we all still wish the doctors weren't so barbaric nowadays.
I can't wait for the medical community to discover and conquer PAIN.

The more salad, the better.

On 4/7/2017 7:34 PM, wrote:
For my part, I always invent things that have been in use for 30 or more years. g
...

Me too. And the others are somewhat better, given that they've been
improved over the 30 years.

When I invent something that's a failure, I think about how many times
in the past such a failure has been invented and forgotten. Only to be
invented again because the previous failures are unknown.

On Saturday, April 8, 2017 at 10:52:55 AM UTC-4, Bob Engelhardt wrote:
On 4/7/2017 7:34 PM, wrote:
For my part, I always invent things that have been in use for 30 or more years. g
...

Me too. And the others are somewhat better, given that they've been
improved over the 30 years.

When I invent something that's a failure, I think about how many times
in the past such a failure has been invented and forgotten. Only to be
invented again because the previous failures are unknown.

Along that line, I found this article about John Goodenough, co-inventor of the lithium-ion battery, to be encouraging. John just invented another new battery, which he says will knock the li-ion battery dead. He's 94 years old and his comments about invention and age are interesting:


https://www.nytimes.com/2017/04/07/o...-old.html?_r=0

--
Ed Huntress

On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and I
wondered if there might be a market for an advanced kind of mechanic's
stethoscope -- something that ought to be a piece of cake for someone
like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the other
end of the shaft. I finally took the whole thing apart and found both
problems, but it wasn't easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap, battery-powered
amplifier, with a mike and a headphone jack, that contained a couple of
active, adjustable audio filters, one high-pass and another low-pass.
Made a notching filter or bandpass filter to make it slick.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

I'm crappy at product marketing, sales, and financing, but good at
"techie" stuff like making this gizmo for cheap in an attractive housing.

So if you want to do the half that's hard for me, give me a call and I'll
do the easy part.

Should be able to do the signal processing digitally, so the hard part
will be making a user interface that allows the pro users to get the most
out of it while making it easy enough for the ordinary guy so it doesn't
just get thrown through the wall.

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

wrote in message
...
On Saturday, April 8, 2017 at 10:52:55 AM UTC-4, Bob Engelhardt wrote:
On 4/7/2017 7:34 PM, wrote:
For my part, I always invent things that have been in use for 30
or more years. g
...

Me too. And the others are somewhat better, given that they've been
improved over the 30 years.

When I invent something that's a failure, I think about how many
times
in the past such a failure has been invented and forgotten. Only to
be
invented again because the previous failures are unknown.

Along that line, I found this article about John Goodenough,
co-inventor of the lithium-ion battery, to be encouraging. John just
invented another new battery, which he says will knock the li-ion
battery dead. He's 94 years old and his comments about invention and
age are interesting:


https://www.nytimes.com/2017/04/07/o...-old.html?_r=0

--
Ed Huntress

=======

When I was a chemist I was interested in aluminum as a battery
electrode, but with the grad school deferment gone the Army offered to
train me in advanced digital electronics and I liked it and stayed
there.
-jsw

On Saturday, April 8, 2017 at 11:45:46 AM UTC-4, Tim Wescott wrote:
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and I
wondered if there might be a market for an advanced kind of mechanic's
stethoscope -- something that ought to be a piece of cake for someone
like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the other
end of the shaft. I finally took the whole thing apart and found both
problems, but it wasn't easy to find them when the motor wasn't running.

So, I wondered about the idea of making a small, cheap, battery-powered
amplifier, with a mike and a headphone jack, that contained a couple of
active, adjustable audio filters, one high-pass and another low-pass.
Made a notching filter or bandpass filter to make it slick.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

I'm crappy at product marketing, sales, and financing, but good at
"techie" stuff like making this gizmo for cheap in an attractive housing.

So if you want to do the half that's hard for me, give me a call and I'll
do the easy part.

Should be able to do the signal processing digitally, so the hard part
will be making a user interface that allows the pro users to get the most
out of it while making it easy enough for the ordinary guy so it doesn't
just get thrown through the wall.

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

That's a tempting thought, but look at it from a marketing perspective: This is a low-tech, analog device, and as Jim and Clare showed, there are slick, digital solutions on the market that even turn a cell phone into an audio spectrum analyzer.

I happen to like these simpler solutions, but I don't think a lot of people would go for it. The market would be really small. So I don't think it's viable except as a hobby thing that one might do for his own use and satisfaction.

I think we should pass on this one.

--
Ed Huntress

"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the hard
part
will be making a user interface that allows the pro users to get the
most
out of it while making it easy enough for the ordinary guy so it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery charger
that can be set to run unattended or used manually to diagnose and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell phone
boosters, this morning it brought back a fully discharged DeWalt NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it, and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they can as
easily destroy a battery as save it.
-jsw

On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the hard
part
will be making a user interface that allows the pro users to get the
most
out of it while making it easy enough for the ordinary guy so it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery charger
that can be set to run unattended or used manually to diagnose and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell phone
boosters, this morning it brought back a fully discharged DeWalt NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it, and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool battery pack can deliver 2,500 Watts, as used in their new 9-in. angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The battery pack looks like it's just a standard 10-cell pack. I've read that the low-end internal resistance for advanced Li-ion cells is around 0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so at full load, which sounds unreasonable. This is a normal-size 36 V battery pack.

What do you think?

--
Ed Huntress

On Saturday, April 8, 2017 at 2:59:13 PM UTC-4, wrote:
On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the hard
part
will be making a user interface that allows the pro users to get the
most
out of it while making it easy enough for the ordinary guy so it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery charger
that can be set to run unattended or used manually to diagnose and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell phone
boosters, this morning it brought back a fully discharged DeWalt NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it, and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool battery pack can deliver 2,500 Watts, as used in their new 9-in. angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The battery pack looks like it's just a standard 10-cell pack. I've read that the low-end internal resistance for advanced Li-ion cells is around 0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so at full load, which sounds unreasonable. This is a normal-size 36 V battery pack.

What do you think?

--
Ed Huntress

Aha, I think I answered my own question. It appears that internal resistance of Li-ion cells vary a lot by type, and the cells used in power tools can be as low as 18 milliohms.

That gives a more reasonable result.

--
Ed Huntress

On Sat, 8 Apr 2017 08:22:00 -0700 (PDT)
wrote:

snip
Along that line, I found this article about John
Goodenough, co-inventor of the lithium-ion battery, to
be encouraging. John just invented another new battery,
which he says will knock the li-ion battery dead. He's 94
years old and his comments about invention and age are
interesting:
https://www.nytimes.com/2017/04/07/o...-old.html?_r=0

Science Friday ran a small segment on new battery tech awhile back:

http://www.sciencefriday.com/segment...ter-batteries/

I don't remember them mentioning John but they covered several things
being researched...

The following was thought to be close to production:

===
The most promising battery the documentary team came across is being
developed by Tufts University Professor Mike Zimmerman, Pogue says.
Hes confronted the problem of lithium-ions explosive liquids head on
€” by eliminating the liquids.

"He's made a solid sheet of a special plastic, a special polymer, that
lets the ions travel back and forth between the electrodes even better
than a liquid electrolyte does," Pogue says. "And yet, because its a
physical barrier, you cant short out like lithium-ion batteries can.

On Saturday, April 8, 2017 at 3:21:12 PM UTC-4, Leon Fisk wrote:
On Sat, 8 Apr 2017 08:22:00 -0700 (PDT)
wrote:

snip
Along that line, I found this article about John
Goodenough, co-inventor of the lithium-ion battery, to
be encouraging. John just invented another new battery,
which he says will knock the li-ion battery dead. He's 94
years old and his comments about invention and age are
interesting:
https://www.nytimes.com/2017/04/07/o...-old.html?_r=0

Science Friday ran a small segment on new battery tech awhile back:

http://www.sciencefriday.com/segment...ter-batteries/

I don't remember them mentioning John but they covered several things
being researched...

The following was thought to be close to production:

===
The most promising battery the documentary team came across is being
developed by Tufts University Professor Mike Zimmerman, Pogue says.
Hes confronted the problem of lithium-ions explosive liquids head on
€” by eliminating the liquids.

"He's made a solid sheet of a special plastic, a special polymer, that
lets the ions travel back and forth between the electrodes even better
than a liquid electrolyte does," Pogue says. "And yet, because its a
physical barrier, you cant short out like lithium-ion batteries can.
So these are plastic electrode batteries..."
===

Interesting stuff

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

Yeah, I'll say it's interesting. The Braga/Goodenough battery uses a glass electrolyte and sodium, as an alternative to lithium:

https://www.forbes.com/sites/jamesco.../#b66f32d4e629

http://pubs.rsc.org/en/Content/Artic...H#!divAbstract

Let's hope one or more of them pan out.

--
Ed Huntress

wrote in message
...
On Saturday, April 8, 2017 at 2:59:13 PM UTC-4,
wrote:
On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the
hard
part
will be making a user interface that allows the pro users to
get the
most
out of it while making it easy enough for the ordinary guy so
it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery
charger
that can be set to run unattended or used manually to diagnose
and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier
this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell
phone
boosters, this morning it brought back a fully discharged DeWalt
NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless
battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it,
and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they
can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool
battery pack can deliver 2,500 Watts, as used in their new 9-in.
angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The
battery pack looks like it's just a standard 10-cell pack. I've
read that the low-end internal resistance for advanced Li-ion cells
is around 0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so
at full load, which sounds unreasonable. This is a normal-size 36 V
battery pack.

What do you think?

--
Ed Huntress

Aha, I think I answered my own question. It appears that internal
resistance of Li-ion cells vary a lot by type, and the cells used in
power tools can be as low as 18 milliohms.

That gives a more reasonable result.

--
Ed Huntress

The little DC Volt/Amp/Watt meters sold to RC hobbyists for their
Lithium packs read over 100A. The cheap tabbed 18650s I'm salvaging
from cell phone portable chargers measure around 75 milliOhms full,
150 nearly discharged.
http://www.ebay.com/itm/like/3317138...&ul_noapp=true

-jsw

On Saturday, April 8, 2017 at 4:48:35 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Saturday, April 8, 2017 at 2:59:13 PM UTC-4,
wrote:
On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the
hard
part
will be making a user interface that allows the pro users to
get the
most
out of it while making it easy enough for the ordinary guy so
it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery
charger
that can be set to run unattended or used manually to diagnose
and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier
this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell
phone
boosters, this morning it brought back a fully discharged DeWalt
NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless
battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it,
and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they
can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool
battery pack can deliver 2,500 Watts, as used in their new 9-in.
angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The
battery pack looks like it's just a standard 10-cell pack. I've
read that the low-end internal resistance for advanced Li-ion cells
is around 0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so
at full load, which sounds unreasonable. This is a normal-size 36 V
battery pack.

What do you think?

--
Ed Huntress

Aha, I think I answered my own question. It appears that internal
resistance of Li-ion cells vary a lot by type, and the cells used in
power tools can be as low as 18 milliohms.

That gives a more reasonable result.

--
Ed Huntress

The little DC Volt/Amp/Watt meters sold to RC hobbyists for their
Lithium packs read over 100A. The cheap tabbed 18650s I'm salvaging
from cell phone portable chargers measure around 75 milliOhms full,
150 nearly discharged.
http://www.ebay.com/itm/like/3317138...&ul_noapp=true

-jsw

Still, it's amazing that those smallish 6.2 Ah Metabo packs will deliver almost 70 A. That seems extremely high, but I guess that's where the technology is now.

--
Ed Huntress

On Sat, 08 Apr 2017 11:59:09 -0700, edhuntress2 wrote:

On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the hard
part will be making a user interface that allows the pro users to get
the most out of it while making it easy enough for the ordinary guy
so it doesn't just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery charger
that can be set to run unattended or used manually to diagnose and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell phone
boosters, this morning it brought back a fully discharged DeWalt NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it, and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool
battery pack can deliver 2,500 Watts, as used in their new 9-in.
angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The
battery pack looks like it's just a standard 10-cell pack. I've read
that the low-end internal resistance for advanced Li-ion cells is around
0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so at
full load, which sounds unreasonable. This is a normal-size 36 V battery
pack.

What do you think?

That's a bit over 11C, which is well within the limits that model
airplane battery packs are run these days. Every day packs come out that
can handle more current for the capacity -- it's probably tools like that
which are driving it.

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

On Sat, 08 Apr 2017 09:59:56 -0700, edhuntress2 wrote:

On Saturday, April 8, 2017 at 11:45:46 AM UTC-4, Tim Wescott wrote:
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g,
and I wondered if there might be a market for an advanced kind of
mechanic's stethoscope -- something that ought to be a piece of cake
for someone like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference
between them made it all but impossible to find the origins of the
noises. One was some mechanical interference between the centrifugal
fan and its housing, at one end of the armature shaft; the other was
vibration resulting from stickiness in the centrifugal throw-out
switch (a fail-safe switch that prevents the gas valve from opening),
at the other end of the shaft. I finally took the whole thing apart
and found both problems, but it wasn't easy to find them when the
motor wasn't running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one high-pass
and another low-pass. Made a notching filter or bandpass filter to
make it slick.

I don't play with engines much these days, but I can recall times
when such a device would have made quick work of tracking down engine
noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.

I'm crappy at product marketing, sales, and financing, but good at
"techie" stuff like making this gizmo for cheap in an attractive
housing.

So if you want to do the half that's hard for me, give me a call and
I'll do the easy part.

Should be able to do the signal processing digitally, so the hard part
will be making a user interface that allows the pro users to get the
most out of it while making it easy enough for the ordinary guy so it
doesn't just get thrown through the wall.

--
Tim Wescott Control systems, embedded software and circuit design I'm
looking for work! See my website if you're interested
http://www.wescottdesign.com

That's a tempting thought, but look at it from a marketing perspective:
This is a low-tech, analog device, and as Jim and Clare showed, there
are slick, digital solutions on the market that even turn a cell phone
into an audio spectrum analyzer.

I happen to like these simpler solutions, but I don't think a lot of
people would go for it. The market would be really small. So I don't
think it's viable except as a hobby thing that one might do for his own
use and satisfaction.

I think we should pass on this one.

Ooh -- maybe the answer is a smartphone app and a companion microphone --
and let people who want to scratch up their own microphone go ahead and
do so.

Hmm. Hmm and hmm. I wonder if it's already done?

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

On Fri, 7 Apr 2017 13:01:13 -0400, "Jim Wilkins"
wrote:

wrote in message
...
Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my furnace
blower, using my usual piece of aquarium hose stuck in my ear g, and
I wondered if there might be a market for an advanced kind of
mechanic's stethoscope -- something that ought to be a piece of cake
for someone like you.

Maybe something like this is on the market. If so, forget it. If not,
consider this:

I had two noises, from different sources, and the interference between
them made it all but impossible to find the origins of the noises. One
was some mechanical interference between the centrifugal fan and its
housing, at one end of the armature shaft; the other was vibration
resulting from stickiness in the centrifugal throw-out switch (a
fail-safe switch that prevents the gas valve from opening), at the
other end of the shaft. I finally took the whole thing apart and found
both problems, but it wasn't easy to find them when the motor wasn't
running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack, that
contained a couple of active, adjustable audio filters, one high-pass
and another low-pass. Made a notching filter or bandpass filter to
make it slick.

I don't play with engines much these days, but I can recall times when
such a device would have made quick work of tracking down engine
noises.

There it is. If you make it and sell it, the idea is yours. Watch out
for patents.


http://www.harborfreight.com/mechani...ope-69913.html


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

"Tim Wescott" wrote in message
...
On Sat, 08 Apr 2017 11:59:09 -0700, edhuntress2 wrote:

On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the
hard
part will be making a user interface that allows the pro users
to get
the most out of it while making it easy enough for the ordinary
guy
so it doesn't just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery
charger
that can be set to run unattended or used manually to diagnose and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier
this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell
phone
boosters, this morning it brought back a fully discharged DeWalt
NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless
battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it, and
I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they
can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool
battery pack can deliver 2,500 Watts, as used in their new 9-in.
angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The
battery pack looks like it's just a standard 10-cell pack. I've
read
that the low-end internal resistance for advanced Li-ion cells is
around
0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so
at
full load, which sounds unreasonable. This is a normal-size 36 V
battery
pack.

What do you think?

That's a bit over 11C, which is well within the limits that model
airplane battery packs are run these days. Every day packs come out
that
can handle more current for the capacity -- it's probably tools like
that
which are driving it.

--
Tim Wescott

This claims 1000A:
https://no.co/gb40

I'm not going to risk testing my Whistler jumpstarter on the HF carbon
pile just to report how much current destroyed it.
-jsw

"Tim Wescott" wrote in message
...
On Sat, 08 Apr 2017 09:59:56 -0700, edhuntress2 wrote:

On Saturday, April 8, 2017 at 11:45:46 AM UTC-4, Tim Wescott wrote:
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.

I spend an hour last night tracking down some noises in my
furnace
blower, using my usual piece of aquarium hose stuck in my ear
g,
and I wondered if there might be a market for an advanced kind
of
mechanic's stethoscope -- something that ought to be a piece of
cake
for someone like you.

Maybe something like this is on the market. If so, forget it. If
not,
consider this:

I had two noises, from different sources, and the interference
between them made it all but impossible to find the origins of
the
noises. One was some mechanical interference between the
centrifugal
fan and its housing, at one end of the armature shaft; the other
was
vibration resulting from stickiness in the centrifugal throw-out
switch (a fail-safe switch that prevents the gas valve from
opening),
at the other end of the shaft. I finally took the whole thing
apart
and found both problems, but it wasn't easy to find them when
the
motor wasn't running.

So, I wondered about the idea of making a small, cheap,
battery-powered amplifier, with a mike and a headphone jack,
that
contained a couple of active, adjustable audio filters, one
high-pass
and another low-pass. Made a notching filter or bandpass filter
to
make it slick.

I don't play with engines much these days, but I can recall
times
when such a device would have made quick work of tracking down
engine
noises.

There it is. If you make it and sell it, the idea is yours.
Watch out
for patents.

I'm crappy at product marketing, sales, and financing, but good at
"techie" stuff like making this gizmo for cheap in an attractive
housing.

So if you want to do the half that's hard for me, give me a call
and
I'll do the easy part.

Should be able to do the signal processing digitally, so the hard
part
will be making a user interface that allows the pro users to get
the
most out of it while making it easy enough for the ordinary guy so
it
doesn't just get thrown through the wall.

--
Tim Wescott Control systems, embedded software and circuit design
I'm
looking for work! See my website if you're interested
http://www.wescottdesign.com

That's a tempting thought, but look at it from a marketing
perspective:
This is a low-tech, analog device, and as Jim and Clare showed,
there
are slick, digital solutions on the market that even turn a cell
phone
into an audio spectrum analyzer.

I happen to like these simpler solutions, but I don't think a lot
of
people would go for it. The market would be really small. So I
don't
think it's viable except as a hobby thing that one might do for his
own
use and satisfaction.

I think we should pass on this one.

Ooh -- maybe the answer is a smartphone app and a companion
microphone --
and let people who want to scratch up their own microphone go ahead
and
do so.

Hmm. Hmm and hmm. I wonder if it's already done?

--
Tim Wescott

http://www.cablechick.com.au/blog/un...d-audio-jacks/

On Sat, 8 Apr 2017 14:00:31 -0700 (PDT), wrote:

On Saturday, April 8, 2017 at 4:48:35 PM UTC-4, Jim Wilkins wrote:
wrote in message
...
On Saturday, April 8, 2017 at 2:59:13 PM UTC-4,
wrote:
On Saturday, April 8, 2017 at 2:00:06 PM UTC-4, Jim Wilkins wrote:
"Tim Wescott" wrote in message
...
On Fri, 07 Apr 2017 08:51:21 -0700, edhuntress2 wrote:

Yo Jim -- and anyone else who may be interested.
.............

Should be able to do the signal processing digitally, so the
hard
part
will be making a user interface that allows the pro users to
get the
most
out of it while making it easy enough for the ordinary guy so
it
doesn't
just get thrown through the wall.

--
Tim Wescott

I can't claim that I'm good at it but I have a lot of experience
designing user interfaces and writing the instruction manuals.

I'm experimenting with a homebrew grid / solar powered battery
charger
that can be set to run unattended or used manually to diagnose
and
restore neglected Lithium, NiCad and Lead-acid batteries. Earlier
this
week it recovered solder-tabbed Li-ion 18650s from "dead" cell
phone
boosters, this morning it brought back a fully discharged DeWalt
NiCad
pack enough for the automatic charger to accept it, and now it's
working on an AGM that went bad in storage. The once useless
battery
delivers 60A.

It's a simple circuit, the hard part is knowing how to use it,
and I
don't have all the answers yet.

Maybe the reason they aren't on the market already is that they
can as
easily destroy a battery as save it.
-jsw

Speaking of Li-ion, Metabo claims that their new 36 V cordless tool
battery pack can deliver 2,500 Watts, as used in their new 9-in.
angle-head grinder.

Maybe my arithmetic is off, but that says roughly 70 A to me. The
battery pack looks like it's just a standard 10-cell pack. I've
read that the low-end internal resistance for advanced Li-ion cells
is around 0.5 Ohms.

My calculation says the battery pack is dissipating 350 Watts or so
at full load, which sounds unreasonable. This is a normal-size 36 V
battery pack.

What do you think?

--
Ed Huntress

Aha, I think I answered my own question. It appears that internal
resistance of Li-ion cells vary a lot by type, and the cells used in
power tools can be as low as 18 milliohms.

That gives a more reasonable result.

--
Ed Huntress

The little DC Volt/Amp/Watt meters sold to RC hobbyists for their
Lithium packs read over 100A. The cheap tabbed 18650s I'm salvaging
from cell phone portable chargers measure around 75 milliOhms full,
150 nearly discharged.
http://www.ebay.com/itm/like/3317138...&ul_noapp=true

-jsw

Still, it's amazing that those smallish 6.2 Ah Metabo packs will deliver almost 70 A. That seems extremely high, but I guess that's where the technology is now.
How about the pocket sized (well, big pockets) lithium booster packs
that will provide 600 amps of cranking power??