--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

--
"Steamboat Ed" Haas : Feeling like Bender in
Hacking the Trailing Edge! : a strong magnetic field...
www.nmpproducts.com
---Decks a-wash in a sea of words---

"steamer" wrote in message
...
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with
various
crawley vermin, which means that, before a log goes into the
fireplace I
first pick it off the pile, then throw it onto the ground and watch
the
little buggers scurry off, then pick it up a second time and take it
to the
fireplace. What I'm thinking is I'll build a really heavy duty
firewood rack
out of steel, then build something that lifts one end a foot or so
off the
ground, then drops it repeatedly, to shake out the unwanted
critters. So
what I need to figure out is how to build a mechanism that's driven
by an
electric motor that will lift, say, 400lbs a foot in the air, then
let go
and do it without falling apart over a loooong winter. Suggestions?

--
"Steamboat Ed" Haas : Feeling like Bender in
Hacking the Trailing Edge! : a strong magnetic field...
www.nmpproducts.com
---Decks a-wash in a sea of words---

Throw poly sheeting over it, flood inside with CO2 from your welder,
asphyxiate the little varmets, and cremate the remains

AWEM

"steamer" wrote in message
...
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the
fireplace. What I'm thinking is I'll build a really heavy duty firewood
rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Wouldn't it just be easier to sticker your woodpile? My parents' woodpile
was in deep shadow all the time and it picked up all kinds of things. I just
put some branches in between the logs, stickering it like a pile of drying
lumber. Once the logs weren't all jammed together the problem disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy metal
at high volume.

--
Ed Huntress

steamer wrote:

--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Up your frequency, Steamer.

This calculator does not extend to the range of frequencies that would
be useful, but you could use the formula to discover what range of
acoustical frequencies the little buggers would dislike.

Surround woodpile with acoustic transducers frequency modulated to
mixmaster their innards and the bugs would probably invade elsewhe

http://hyperphysics.phy-astr.gsu.edu...cavity.html#c4

--Winston

On Mon, 8 Oct 2007 15:34:54 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"steamer" wrote in message
.. .
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the
fireplace. What I'm thinking is I'll build a really heavy duty firewood
rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Wouldn't it just be easier to sticker your woodpile? My parents' woodpile
was in deep shadow all the time and it picked up all kinds of things. I just
put some branches in between the logs, stickering it like a pile of drying
lumber. Once the logs weren't all jammed together the problem disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Does that really work?


Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy metal
at high volume.

Erm, does heavy metal music ward off hopeless darkness and wetness in
Jersey, Ed?

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

"Larry Jaques" wrote in message
...
On Mon, 8 Oct 2007 15:34:54 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"steamer" wrote in message
. ..
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the
fireplace. What I'm thinking is I'll build a really heavy duty firewood
rack
out of steel, then build something that lifts one end a foot or so off
the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by
an
electric motor that will lift, say, 400lbs a foot in the air, then let
go
and do it without falling apart over a loooong winter. Suggestions?

Wouldn't it just be easier to sticker your woodpile? My parents' woodpile
was in deep shadow all the time and it picked up all kinds of things. I
just
put some branches in between the logs, stickering it like a pile of drying
lumber. Once the logs weren't all jammed together the problem disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Does that really work?

Sure. It's a PITA to sticker everything up, but it works.


Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy metal
at high volume.

Erm, does heavy metal music ward off hopeless darkness and wetness in
Jersey, Ed?

Reggaeton is what we use here. And if you've never heard reggaeton music,
it's hard to appreciate why it kills mold and termites.

--
Ed Huntress

On Mon, 8 Oct 2007 18:31:00 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Larry Jaques" wrote in message
.. .
On Mon, 8 Oct 2007 15:34:54 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

put some branches in between the logs, stickering it like a pile of drying
lumber. Once the logs weren't all jammed together the problem disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Does that really work?

Sure. It's a PITA to sticker everything up, but it works.


Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy metal
at high volume.

Erm, does heavy metal music ward off hopeless darkness and wetness in
Jersey, Ed?

Reggaeton is what we use here. And if you've never heard reggaeton music,
it's hard to appreciate why it kills mold and termites.

Ohmyfreakin'god. It's a hispanic version of reggaed rap. I now
understand why it kills and maims so well. http://tinyurl.com/2jnodg
for those with -real- balls (and no sense whatsoever)

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

"Larry Jaques" wrote in message
...
On Mon, 8 Oct 2007 18:31:00 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Larry Jaques" wrote in message
. ..
On Mon, 8 Oct 2007 15:34:54 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

put some branches in between the logs, stickering it like a pile of
drying
lumber. Once the logs weren't all jammed together the problem
disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Does that really work?

Sure. It's a PITA to sticker everything up, but it works.


Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy
metal
at high volume.

Erm, does heavy metal music ward off hopeless darkness and wetness in
Jersey, Ed?

Reggaeton is what we use here. And if you've never heard reggaeton music,
it's hard to appreciate why it kills mold and termites.

Ohmyfreakin'god. It's a hispanic version of reggaed rap. I now
understand why it kills and maims so well. http://tinyurl.com/2jnodg
for those with -real- balls (and no sense whatsoever)

You'll notice, if you listen to enough of it, that the EcoBlast rechargeable
air horn is one of the regular instruments. d8-)

--
Ed Huntress

Ed Huntress wrote:

"steamer" wrote in message
...
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the
fireplace. What I'm thinking is I'll build a really heavy duty firewood
rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Wouldn't it just be easier to sticker your woodpile? My parents' woodpile
was in deep shadow all the time and it picked up all kinds of things. I just
put some branches in between the logs, stickering it like a pile of drying
lumber. Once the logs weren't all jammed together the problem disappeared.
It stayed dryer, too. Don't let falling leaves get in there.

Or is the place hopelessly dark and wet?

You could try putting some big speakers near the pile and play heavy metal
at high volume.


Use rap, and any self respecting bug will leave, or commit suicide.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On 2007-10-08, Ed Huntress wrote:
You could try putting some big speakers near the pile and play heavy metal
at high volume.

I have a small clock radio in my shed with Rush Limbaugh. Keeps mice
away.

i

On Mon, 08 Oct 2007 20:00:11 GMT, Winston
wrote:

steamer wrote:

--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Up your frequency, Steamer.

This calculator does not extend to the range of frequencies that would
be useful, but you could use the formula to discover what range of
acoustical frequencies the little buggers would dislike.

Surround woodpile with acoustic transducers frequency modulated to
mixmaster their innards and the bugs would probably invade elsewhe

http://hyperphysics.phy-astr.gsu.edu...cavity.html#c4

--Winston

Mice and other small rodents are repelled by frequencies in the region
of 25KHz to 35KHz. It needs to be fairly intense (93 dB or better)
and it's best if it is intermittent and frequency-modulated at a low
rate. I used cheap Motorola piezo tweeters, sometimes as little as
$3.95 each.

Tried in two northwoods cabins, worked in both. Man, did they come
outta the woodwork and scurry for the woods when I first turned that
sucker on upon arrival after being away for a while.

On Mon, 8 Oct 2007 19:30:05 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Larry Jaques" wrote in message
.. .
On Mon, 8 Oct 2007 18:31:00 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

Reggaeton is what we use here. And if you've never heard reggaeton music,
it's hard to appreciate why it kills mold and termites.

Ohmyfreakin'god. It's a hispanic version of reggaed rap. I now
understand why it kills and maims so well. http://tinyurl.com/2jnodg
for those with -real- balls (and no sense whatsoever)

You'll notice, if you listen to enough of it, that the EcoBlast rechargeable
air horn is one of the regular instruments. d8-)

Thanks or the wonderful opportunity, Ed, but I'll pass.

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

"Ed Huntress" fired this volley in
:

You could try putting some big speakers near the pile and play heavy
metal at high volume.



No, Ed. You have to play "Beatle music".

LLoyd

"Larry Jaques" wrote in message
...
On Mon, 8 Oct 2007 19:30:05 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Larry Jaques" wrote in message
. ..
On Mon, 8 Oct 2007 18:31:00 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

Reggaeton is what we use here. And if you've never heard reggaeton
music,
it's hard to appreciate why it kills mold and termites.

Ohmyfreakin'god. It's a hispanic version of reggaed rap. I now
understand why it kills and maims so well. http://tinyurl.com/2jnodg
for those with -real- balls (and no sense whatsoever)

You'll notice, if you listen to enough of it, that the EcoBlast
rechargeable
air horn is one of the regular instruments. d8-)

Thanks or the wonderful opportunity, Ed, but I'll pass.

I should have told you what it's good for. I listen to the reggaeton station
in NYC when I'm exhausted and driving late at night, and the coffee doesn't
work anymore. The air horns, when they're timed right, keep jerking you to
attention.

However, I think the whole genre is an example of what happens when you give
kids too many toys, with no parental controls.

--
Ed Huntress

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"Ed Huntress" fired this volley in
:

You could try putting some big speakers near the pile and play heavy
metal at high volume.



No, Ed. You have to play "Beatle music".

You will pay for that one, Lloyd, if not now, then in the afterlife.

--
Ed Huntress

Don Foreman wrote:
On Mon, 08 Oct 2007 20:00:11 GMT, Winston
wrote:


steamer wrote:


--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Up your frequency, Steamer.

This calculator does not extend to the range of frequencies that would
be useful, but you could use the formula to discover what range of
acoustical frequencies the little buggers would dislike.

Surround woodpile with acoustic transducers frequency modulated to
mixmaster their innards and the bugs would probably invade elsewhe

http://hyperphysics.phy-astr.gsu.edu...cavity.html#c4

--Winston


Mice and other small rodents are repelled by frequencies in the region
of 25KHz to 35KHz. It needs to be fairly intense (93 dB or better)
and it's best if it is intermittent and frequency-modulated at a low
rate. I used cheap Motorola piezo tweeters, sometimes as little as
$3.95 each.

Tried in two northwoods cabins, worked in both. Man, did they come
outta the woodwork and scurry for the woods when I first turned that
sucker on upon arrival after being away for a while.

Digikey sells transducers in 40 KHz, 92 Khz, 150 KHz and 215 KHz flavors:

http://search.digikey.com/scripts/Dk...rds=transducer

http://media.paisley.ac.uk/~davison/...cct/u_cct.html

--Winston

On Mon, 08 Oct 2007 19:21:41 +0000, steamer wrote:

--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the fireplace. What I'm thinking is I'll build a really heavy duty
firewood rack out of steel, then build something that lifts one end a foot
or so off the ground, then drops it repeatedly, to shake out the unwanted
critters. So what I need to figure out is how to build a mechanism that's
driven by an electric motor that will lift, say, 400lbs a foot in the air,
then let go and do it without falling apart over a loooong winter.
Suggestions?

Adapt an old paint shaker?

Good Luck!
Rich

On Mon, 08 Oct 2007 22:05:42 -0500, Don Foreman
wrote:


Mice and other small rodents are repelled by frequencies in the region
of 25KHz to 35KHz. It needs to be fairly intense (93 dB or better)
and it's best if it is intermittent and frequency-modulated at a low
rate. I used cheap Motorola piezo tweeters, sometimes as little as
$3.95 each.

Tried in two northwoods cabins, worked in both. Man, did they come
outta the woodwork and scurry for the woods when I first turned that
sucker on upon arrival after being away for a while.


Hey Don,

WOW!! 93 db. What will that do to "other" local inhabitants, like
the neighbourhood dogs and cats?

And will that freq & audio level attract other species, like crickets
or something?

Take care.

Brian Lawson,
Bothwell, Ontario.

On Tue, 9 Oct 2007 10:33:39 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

I should have told you what it's good for. I listen to the reggaeton station
in NYC when I'm exhausted and driving late at night, and the coffee doesn't
work anymore. The air horns, when they're timed right, keep jerking you to
attention.

My, how quaint.


However, I think the whole genre is an example of what happens when you give
kids too many toys, with no parental controls.

Giving kids (who have no sense of rhythm, are tone-deaf, angry, and on
drugs and alcohol) instruments and recording equipment doesn't do
justice to the industry, that's for certain sure.

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

On Tue, 09 Oct 2007 16:22:17 GMT, Winston
wrote:

Don Foreman wrote:
On Mon, 08 Oct 2007 20:00:11 GMT, Winston
wrote:


steamer wrote:


--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

Up your frequency, Steamer.

This calculator does not extend to the range of frequencies that would
be useful, but you could use the formula to discover what range of
acoustical frequencies the little buggers would dislike.

Surround woodpile with acoustic transducers frequency modulated to
mixmaster their innards and the bugs would probably invade elsewhe

http://hyperphysics.phy-astr.gsu.edu...cavity.html#c4

--Winston


Mice and other small rodents are repelled by frequencies in the region
of 25KHz to 35KHz. It needs to be fairly intense (93 dB or better)
and it's best if it is intermittent and frequency-modulated at a low
rate. I used cheap Motorola piezo tweeters, sometimes as little as
$3.95 each.

Tried in two northwoods cabins, worked in both. Man, did they come
outta the woodwork and scurry for the woods when I first turned that
sucker on upon arrival after being away for a while.

Digikey sells transducers in 40 KHz, 92 Khz, 150 KHz and 215 KHz flavors:

http://search.digikey.com/scripts/Dk...rds=transducer

http://media.paisley.ac.uk/~davison/...cct/u_cct.html

--Winston

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

On Tue, 09 Oct 2007 18:06:24 -0400, Brian Lawson
wrote:

On Mon, 08 Oct 2007 22:05:42 -0500, Don Foreman
wrote:


Mice and other small rodents are repelled by frequencies in the region
of 25KHz to 35KHz. It needs to be fairly intense (93 dB or better)
and it's best if it is intermittent and frequency-modulated at a low
rate. I used cheap Motorola piezo tweeters, sometimes as little as
$3.95 each.

Tried in two northwoods cabins, worked in both. Man, did they come
outta the woodwork and scurry for the woods when I first turned that
sucker on upon arrival after being away for a while.


Hey Don,

WOW!! 93 db. What will that do to "other" local inhabitants, like
the neighbourhood dogs and cats?

Probably not. The larger the critter the lower the highest frequency
heard. I think dogs 'n cats are only good to about 25 KHz or so.
Also, it'd have to be highly directional to have much effect beyond 50
feet or so. And anyway, who cares if it repels stray dogs 'n cats?

And will that freq & audio level attract other species, like crickets
or something?

It is said to repel cockroaches, but I can't vouch for that. The
cabin was not festooned with horny bats.

Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Bookmarked. Thanks!

--Winston

On Wed, 10 Oct 2007 11:12:20 GMT, Winston
wrote:

Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Bookmarked. Thanks!

--Winston

I used an NE566 or LM566 voltage-controlled oscillator chip so I could
get some frequency sweep. Sweep freq was 60 Hz. This chip is now
long obsolete but there may be others. Ah, Electronic Goldmine has
some, $5.95 ea. The frequency sweep makes a big contribution to how
irritating the sound is.

I put a switch on mine so it could be switched down to a range audible
to humans. When folks would scoff (because commercial units available
did not work), I invited them to hit that switch and stay in the room
with it for more than 10 seconds. One second was usually plenty for
them.

Don Foreman wrote:
On Wed, 10 Oct 2007 11:12:20 GMT, Winston
wrote:


Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Bookmarked. Thanks!

--Winston


I used an NE566 or LM566 voltage-controlled oscillator chip so I could
get some frequency sweep. Sweep freq was 60 Hz. This chip is now
long obsolete but there may be others. Ah, Electronic Goldmine has
some, $5.95 ea. The frequency sweep makes a big contribution to how
irritating the sound is.

I put a switch on mine so it could be switched down to a range audible
to humans. When folks would scoff (because commercial units available
did not work), I invited them to hit that switch and stay in the room
with it for more than 10 seconds. One second was usually plenty for
them.

Changed their mind, did it?

Here's your tweeter, a buck cheaper, for multiple units around those
larger woodpiles:
http://docs.bgmicro.com/pdf/page22.pdf (Middle of page near the bottom.)
Is that really 96 db for only two watts? Shazam!

I didn't see a bandpass diagram for that tweeter but I wonder what the
upper frequency limit is. I would like to accomodate smaller critters.
(Ants come to mind for some reason).

--Winston

On Wed, 10 Oct 2007 18:05:36 GMT, Winston
wrote:



Here's your tweeter, a buck cheaper, for multiple units around those
larger woodpiles:
http://docs.bgmicro.com/pdf/page22.pdf (Middle of page near the bottom.)
Is that really 96 db for only two watts? Shazam!



I didn't see a bandpass diagram for that tweeter but I wonder what the
upper frequency limit is. I would like to accomodate smaller critters.
(Ants come to mind for some reason).

They vary. Some of the silver ones shaped like that from Radio Shack
would go up to 40 KHz. They had a spectrum plot printed on the box.
About any of them will do 27 KHz or so.

Some technical specs he

http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Using watts is misleading because these piezo devices look
electrically like an 0.13 uF capacitor. The electrical load that they
present varies with frequency. The 50W rating they refer to is
probably referred to 8 ohms, or 20 VRMS. I drove mine at about that
level. At 30 KHz the Z is about j40 ohms, which would be about 0.5 amp
RMS, which does indeed compute to 2 watts. They ran slightly warm. I
reckon they were putting out considerably more than 96 dB. The 96 dB
@ 1 meter is measured with 2.83 volts RMS applied.

Note that the rectangular KSN1016A goes to 40 KHz.

"steamer" wrote in message
...
--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to
the
fireplace. What I'm thinking is I'll build a really heavy duty firewood
rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

--
"Steamboat Ed" Haas

sorry, i'm not exactly sure what you mean.
i think if it were me and the insects bothered me that much i'd roll the
wood through a trommel and into my firewood hauling bin/wagon.
http://www.infowest.com/personal/w/w...r/trommel.html
even that would be a pain in the ass.
i'd think the bugs (you're just referring to insects, right?) wouldn't leave
if it was only dropping the entire pile repeatedly. i'd think they'd just
fall down onto the next piece of wood. i don't even know if they'd leave if
you put the rack (made w/ expanded steel mesh and like 2" square tubing) on
like coil truck springs with a massive vibrator mechanism (like a "plate
tamper"
http://webservices.siriusweblabs.com...114/MVC60H.jpg
bolted to it. (i remember an episode on tv of how they built the SAC base
inside that mountain in CO http://en.wikipedia.org/wiki/Cheyenne_Mountain
and put the whole thing on MASSIVE coil springs. lol.) i guess the sonic
cure would be easiest, fastest, cheapest. the vibrator rack might be funny
though, take a video of it and post it to youtube. "shakin' my firewood"

b.w.

Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Freq response?

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

On Wed, 10 Oct 2007 19:31:37 -0700, Larry Jaques
wrote:

Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Freq response?

Not really meaningful. Transistors were switching, rise & fall of
probably a microsecond or two. No problem producing a squarewave up
to 40 KHz. A 47-ohm series resistor in conjunction with the
capacitance of the speaker rounded this off to a semblance of a sine
wave.

Don Foreman wrote:
On Wed, 10 Oct 2007 18:05:36 GMT, Winston
wrote:



Here's your tweeter, a buck cheaper, for multiple units around those
larger woodpiles:
http://docs.bgmicro.com/pdf/page22.pdf (Middle of page near the bottom.)
Is that really 96 db for only two watts? Shazam!



I didn't see a bandpass diagram for that tweeter but I wonder what the
upper frequency limit is. I would like to accomodate smaller critters.
(Ants come to mind for some reason).


They vary. Some of the silver ones shaped like that from Radio Shack
would go up to 40 KHz. They had a spectrum plot printed on the box.
About any of them will do 27 KHz or so.

Some technical specs he

http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Using watts is misleading because these piezo devices look
electrically like an 0.13 uF capacitor. The electrical load that they
present varies with frequency. The 50W rating they refer to is
probably referred to 8 ohms, or 20 VRMS. I drove mine at about that
level. At 30 KHz the Z is about j40 ohms, which would be about 0.5 amp
RMS, which does indeed compute to 2 watts. They ran slightly warm. I
reckon they were putting out considerably more than 96 dB. The 96 dB
@ 1 meter is measured with 2.83 volts RMS applied.

Note that the rectangular KSN1016A goes to 40 KHz.


http://www.adelcom.net/MOTOROLA_ksn1016a.htm

Radical! Thanks again.

--Winston

On Wed, 10 Oct 2007 22:23:51 -0500, with neither quill nor qualm, Don
Foreman quickly quoth:

On Wed, 10 Oct 2007 19:31:37 -0700, Larry Jaques
wrote:

Don Foreman wrote:
(..)

Those 'ducers aren't good for this. They're either too pricey, too
wimpy or have very limited bandwidth.

Here's what I used:

http://www.electronicpartsforless.co...id=36&df id=1

If ya use a 555 or 556, it needs a simple power amp comprised of a
coupla transistors working from +/- 15 volts.

Freq response?

Not really meaningful.

It could be, if they don't do much over 20KHz. Some of the cheaper
piezos were built for audio freqs and drop off quickly above it.


Transistors were switching, rise & fall of
probably a microsecond or two. No problem producing a squarewave up
to 40 KHz. A 47-ohm series resistor in conjunction with the
capacitance of the speaker rounded this off to a semblance of a sine
wave.

Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

Quoth Sir Larry:

Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Not even muffler bearings.

I think they refer to the same wire-wound style as the 10 W beige parts
shown in:
http://www2.neufeld.newton.ks.us/ima...2/100_2505.JPG

--Winston

On Thu, 11 Oct 2007 06:12:50 -0700, Larry Jaques
wrote:


Transistors were switching, rise & fall of
probably a microsecond or two. No problem producing a squarewave up
to 40 KHz. A 47-ohm series resistor in conjunction with the
capacitance of the speaker rounded this off to a semblance of a sine
wave.

Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

They claim it's to enable use of an L-pad. 30 watts is ridiculous, 1
watt would be plenty.

A shunt resistor would be better for use with an L-pad. It might
indeed need to be 30 W, and it should be used with a crossover.

Some think a piezo tweeter sounds better with series resistance.

None of the above applies to a ratzapper.

On Thu, 11 Oct 2007 14:08:15 GMT, with neither quill nor qualm,
Winston quickly quoth:

Quoth Sir Larry:

Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Not even muffler bearings.

I think they refer to the same wire-wound style as the 10 W beige parts
shown in:
http://www2.neufeld.newton.ks.us/ima...2/100_2505.JPG

Huh. Then why didn't they just _say_ "standard power resistors"?


--
Ultimately, the only power to which man should aspire
is that which he exercises over himself.
-- Elie Wiesel

Larry Jaques insisted:
On Thu, 11 Oct 2007 14:08:15 GMT, with neither quill nor qualm,
Winston quickly quoth:


Quoth Sir Larry:


Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Not even muffler bearings.

I think they refer to the same wire-wound style as the 10 W beige parts
shown in:
http://www2.neufeld.newton.ks.us/ima...2/100_2505.JPG


Huh. Then why didn't they just _say_ "standard power resistors"?

That would make the idea, dare I say it? Accessible.
And We Can't Have That. Now can we?



--Winston

On Oct 8, 12:21 pm, steamer wrote:
... a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off

There's a feature of cold-blooded insect life that can be used to
your advantage here. They flee hot areas (above 130 F), or
die there. If you can put your wood into a solar kiln (just a box
with black sides and maybe a couple of white reflector panels),
and get it hot on a sunny day, the insects which are ambulatory
wil leave and the eggs (which can't leave) will never hatch.

The lumber industry is just as bothered by those six-leggers as
you could ever be. Not to mention the isopods and others...

On Thu, 11 Oct 2007 13:56:15 -0700, Larry Jaques wrote:
On Thu, 11 Oct 2007 14:08:15 GMT, with neither quill nor qualm, Winston
Quoth Sir Larry:

Bueno. What's this 20 ohm 30 watt "square ohm" resistor they're
talking about? Anything like "cam dusters" or "Kanutin valves"?
http://www.adelcom.net/MOTOROLA_ksn1005b.htm

Not even muffler bearings.

I think they refer to the same wire-wound style as the 10 W beige parts
shown in:
http://www2.neufeld.newton.ks.us/ima...2/100_2505.JPG

Huh. Then why didn't they just _say_ "standard power resistors"?

Probably becaue there is no such thing as a "standard power resistor".
They come in all sorts of shapes and sizes.

The ones in the pic, I've heard called "sandstone". There are also
the tubular ones, and the metal ones with bolt holes, like the top two
he
http://www.globalsources.com/gsol/I/...7757/18632.htm

Hope This Helps!
Rich

--Looking for a solution to a little design problem. The situation
arises due to a firewood pile that's periodically infested with various
crawley vermin, which means that, before a log goes into the fireplace I
first pick it off the pile, then throw it onto the ground and watch the
little buggers scurry off, then pick it up a second time and take it to the
fireplace. What I'm thinking is I'll build a really heavy duty firewood rack
out of steel, then build something that lifts one end a foot or so off the
ground, then drops it repeatedly, to shake out the unwanted critters. So
what I need to figure out is how to build a mechanism that's driven by an
electric motor that will lift, say, 400lbs a foot in the air, then let go
and do it without falling apart over a loooong winter. Suggestions?

--
"Steamboat Ed" Haas : Feeling like Bender in
Hacking the Trailing Edge! : a strong magnetic field...
www.nmpproducts.com
---Decks a-wash in a sea of words---
If'n you got a tractor with 3-point hitch and hydraulics, a good ol'
post driver would be the ticket.... however, just jarring the little
buggers probably ain't enough to get rid of all of 'em.
Ken.