"HeyBub" wrote in message
m...
Stormin Mormon wrote:
Some inverters put out modified sine, which reads about 90
volts on a digital meter. My suggestion is try a filament
lamp of some kind, or maybe a hair dryer. Old style toaster,
is also good. If the toaster works, you're likelly getting
modified sine. And the machine is OK.

I have an ETQ which has really done a good job. Never
checked the voltages. It runs a toaster (Yes, I really did
plug in a toaster, and try it.) Also runs a furnace, guy I
knew had his power out, couple years ago. The ETQ ran his
furnace nicely.

Ah, good catch! If the generator is putting out a modified sine wave and
the
meter is measuring peak-to-peak, there's gonna be a difference.



Why would a single phase generator be putting out a square wave? I imagine
it may be somewhat fuzzy, but I think it pretty much has to be a sine wave.

It's incredibly unlikely that a small generator would put
out square wave, or mod sine. It's so much easier for a
small, inexpensive generator to spin a coil, and produce
natural sine.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Ulysses" wrote in message
...


Why would a single phase generator be putting out a square
wave? I imagine
it may be somewhat fuzzy, but I think it pretty much has to
be a sine wave.

On Jun 24, 2:43�pm, "Stormin Mormon"
wrote:
It's incredibly unlikely that a small generator would put
out square wave, or mod sine. It's so much easier for a
small, inexpensive generator to spin a coil, and produce
natural sine.

--
Christopher A. Young
Learn more about Jesus
�www.lds.org
.

"Ulysses" wrote in message

...

Why would a single phase generator be putting out a square
wave? �I imagine
it may be somewhat fuzzy, but I think it pretty much has to
be a sine wave.

a buddy put several generators on a techtronics scope, none were nice
sine waves like the power company provides

"Stormin Mormon" wrote in
:

It's incredibly unlikely that a small generator would put
out square wave, or mod sine. It's so much easier for a
small, inexpensive generator to spin a coil, and produce
natural sine.


somehow someone was talking about inverters,which can either output square
wave,modified or quasi-sq.wave,or sine wave AC.

Why it came up about generators,I don't know.
An AC generator is always going to output a sine wave.

--
Jim Yanik
jyanik
at
kua.net

I'd think so, at least the spinning coil ones. Honda has
some that have "inverter technology". Maybe the guy with the
oscilloscope is picking up some harmonics, and other noise.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Jim Yanik" wrote in message
...

An AC generator is always going to output a sine wave.

--
Jim Yanik
jyanik
at
kua.net

"Stormin Mormon" wrote in
:

I'd think so, at least the spinning coil ones. Honda has
some that have "inverter technology". Maybe the guy with the
oscilloscope is picking up some harmonics, and other noise.


http://www.hondapowerequipment.com/p...t.aspx?asset=g
g_inverteradvantage

the generator makes "multi-phase AC",converts to DC,then uses an inverter
to get back to 60hz AC.

it's very possible it makes a lot of electrical noise.

--
Jim Yanik
jyanik
at
kua.net

"Jim Yanik" wrote in message
...
"Stormin Mormon" wrote in
:

I'd think so, at least the spinning coil ones. Honda has
some that have "inverter technology". Maybe the guy with the
oscilloscope is picking up some harmonics, and other noise.



http://www.hondapowerequipment.com/p...t.aspx?asset=g
g_inverteradvantage

the generator makes "multi-phase AC",converts to DC,then uses an inverter
to get back to 60hz AC.

it's very possible it makes a lot of electrical noise.

You guys lost me. A Coleman is not a Honda inverter generator. Besides
that, Honda claims their sine wave is better than what you get from your
local utility.


--
Jim Yanik
jyanik
at
kua.net

"Ulysses" wrote in
:


"Jim Yanik" wrote in message
...
"Stormin Mormon" wrote in
:

I'd think so, at least the spinning coil ones. Honda has
some that have "inverter technology". Maybe the guy with the
oscilloscope is picking up some harmonics, and other noise.



http://www.hondapowerequipment.com/p...ntent.aspx?ass
et=g
g_inverteradvantage

the generator makes "multi-phase AC",converts to DC,then uses an
inverter to get back to 60hz AC.

it's very possible it makes a lot of electrical noise.

You guys lost me. A Coleman is not a Honda inverter generator.

Well,the OP mentioned "inverters" and MY post questioned why an inverter
was used when the generator already makes a sine wave output.
Then someone else mentioned Honda,and I researched that to answer my own
question.

Besides that, Honda claims their sine wave is better than what you get
from your local utility.


--
Jim Yanik
jyanik
at
kua.net




generating a sine wave from a DC supply requires switching large
currents.the switchuing generates harmonics.

Now,the sine wave output may be very clean and right on freq,but the
inverter's switching circuitry may radiate those harmonics,that could be
picked up by other instruments.
It takes very careful design to minimize radiated noise.

--
Jim Yanik
jyanik
at
kua.net

I have a similar problem with my 1850 but the output voltage drops at
about 1100 watts load. The diodes appear ok, but I have no way to test
the varistors in parallel with them.
The problem started with a snapped governor lever which would have
caused very high engine speed. That would have created a very high
output voltage which I suspect could have damaged the diodes and/or
varistors causing them to fail as the load increases. I hope to replace
both and see what happens. Any thoughts?

I've put together a small page showing the repairs.
http://members.rennlist.org/warren/1850.html

You have simply got to be an engineer. No one else puts that
much detail and work into repairing something.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"warren" wrote in message
...

I have a similar problem with my 1850 but the output voltage
drops at
about 1100 watts load. The diodes appear ok, but I have no
way to test
the varistors in parallel with them.
The problem started with a snapped governor lever which
would have
caused very high engine speed. That would have created a
very high
output voltage which I suspect could have damaged the diodes
and/or
varistors causing them to fail as the load increases. I
hope to replace
both and see what happens. Any thoughts?

I've put together a small page showing the repairs.
http://members.rennlist.org/warren/1850.html

Probably a good thing you didn't visit my home page...




Stormin Mormon wrote:
You have simply got to be an engineer. No one else puts that
much detail and work into repairing something.

On Tue, 22 Sep 2009 17:24:48 -0300, warren
wrote:


I have a similar problem with my 1850 but the output voltage drops at
about 1100 watts load. The diodes appear ok, but I have no way to test
the varistors in parallel with them.
The problem started with a snapped governor lever which would have
caused very high engine speed. That would have created a very high
output voltage

Well, I never understood why, but, in automobile terms, I thought
alternators had higher output at low speeds than generators did, but
lower output at high speeds. Or that the voltage woudln't increase
that much. A) Does your Powermate use an alternator? B) Am I right
about what I thought. C) Would that make you wrong?

which I suspect could have damaged the diodes and/or
varistors causing them to fail as the load increases.

Did the load increase? Or did the load stay the same and output
voltage increase? But I guess the second would make the voltage
across both the dioades and the varistors increase, which is what you
had in mind. Still, would that be enough to make them fail? I guess
if they were not much better than the expected output one or both
would.

I hope to replace
both and see what happens. Any thoughts?

I've put together a small page showing the repairs.
http://members.rennlist.org/warren/1850.html

The generator operates at a constant speed of 3600RPM in order to
produce a 60Hz output.

Under no load the output is about 120VAC. It remains relatively
constant up to about 1100 watts load. After that as the load increases
it drops considerably, down to about 90VAC with a 1300 watt load. It
should be capable of 1500 watts output continuously at 120VAC.

The governor in the engine failed and would have caused it to rev very
high at full throttle. During this time the output voltage would have
gone very high, and possibly caused damage to the diodes and/or the
varistors. These components are on the rotor, and somehow connect with
the field coils. I'm still trying to understand better how a brushless
output generator somewhat self regulates its output voltage.

I've repaired the governor problem, and the engine works well now.
However the next step is to ensure all components on the generator side
are good in order to produce the proper power output.



I've put together a small page showing the repairs.
http://members.rennlist.org/warren/1850.html

The generator operates at a constant speed of 3600RPM in order to
produce a 60Hz output.

Under no load the output is about 120VAC. It remains relatively
constant up to about 1100 watts load. After that as the load increases
it drops considerably, down to about 90VAC with a 1300 watt load. It
should be capable of 1500 watts output continuously at 120VAC.

The governor in the engine failed and would have caused it to rev very
high at full throttle. During this time the output voltage would have
gone very high, and possibly caused damage to the diodes and/or the
varistors. These components are on the rotor, and somehow connect with
the field coils. I'm still trying to understand better how a brushless
output generator somewhat self regulates its output voltage.

I've repaired the governor problem, and the engine works well now.
However the next step is to ensure all components on the generator side
are good in order to produce the proper power output.



I've put together a small page showing the repairs.
http://members.rennlist.org/warren/1850.html

I also have an 1850 coleman that i lost total A C output. I thaought it just had to be the capacitor
.. i replaced it... Nothing.same thing ...no voltage. Im about to give up on it.

On 5/12/2019 3:36 AM, wrote:
I also have an 1850 coleman that i lost total A C output. I thaought it just had to be the capacitor
. i replaced it... Nothing.same thing ...no voltage. Im about to give up on it.

Flash the field windings , it's lost the residual magnetism that it
needs to start the generation process . I had the same problem with a
Briggs unit a few years back .

--
Snag
Yes , I'm old
and crochety - and armed .
Get outta my woods !

On Sun, 12 May 2019 06:29:29 -0500, Terry Coombs
wrote:

On 5/12/2019 3:36 AM, wrote:
I also have an 1850 coleman that i lost total A C output. I thaought it just had to be the capacitor
. i replaced it... Nothing.same thing ...no voltage. Im about to give up on it.

Flash the field windings , it's lost the residual magnetism that it
needs to start the generation process . I had the same problem with a
Briggs unit a few years back .
sounds like MABRR it was shut down under full load? That sometimes
collapses the kagnetic feild causing the generator to faik to
energize. Flashing often fixes this. Shutting off loads before
shutting down the generator odten prevents the problem

On 5/12/2019 4:44 PM, Clare Snyder wrote:
On Sun, 12 May 2019 06:29:29 -0500, Terry Coombs
wrote:

On 5/12/2019 3:36 AM, wrote:
I also have an 1850 coleman that i lost total A C output. I thaought it just had to be the capacitor
. i replaced it... Nothing.same thing ...no voltage. Im about to give up on it.
Flash the field windings , it's lost the residual magnetism that it
needs to start the generation process . I had the same problem with a
Briggs unit a few years back .
sounds like MABRR it was shut down under full load? That sometimes
collapses the kagnetic feild causing the generator to faik to
energize. Flashing often fixes this. Shutting off loads before
shutting down the generator odten prevents the problem

Â* I think that's what happened to mine . I learned there is a way to
get it going by plugging a drill motor into one of the outlets then
spinning that drill with another (while holding the trigger down) while
the generator is running . I already had mine partly disassembled so I
did it with a 12V battery . Been working fine ever since .

--
Snag
Yes , I'm old
and crochety - and armed .
Get outta my woods !