Thanks Bob, I realize that these units are not the best solution for this job. Idea cancelled !!
I found some 24 and 48 volt DC power supplies that may work much better and with greater efficiency.
(120VAC to 24DC @ 50 amps) I can drive the power supply directly from the generator 120VAC outlet.

cheers,
veggie

Can anyone shed some light on the principle of operation for these little units.
Here's the description from the Ebay advert....
(Translation is not the best)

==============================
Model: 3500 (belt type)
Rated speed: 2800-4000 rpm/min
Voltage: 220V
Power: 3500 (actual power 1000W)
Function: Can be used with light bulbs, not home appliances

The special model for lighting is a brushless permanent magnet alternator, with a voltage stabilizer in the machine, and the working frequency is high frequency. It is only suitable for pure resistance household appliances such as lighting, TV, rice cooker, heating birdcage, electric stove, etc., and cannot drive electric fans. , Computers, refrigerators, washing machines, induction cookers, air conditioners, motors, angle grinders, water pumps, electric hoists and other electrical induction household appliances!

    The household frequency 50Hz model is a brushless excitation alternator. There is no voltage stabilizer in the machine. The working frequency is 50Hz. It can be used with electric fans, computers, refrigerators, washing machines, induction cookers, air conditioners, motors, angle grinders, water pumps, electric hoists, etc. Motor induction household appliances! When the generator is used for induction household appliances such as electric fans, refrigerators, washing machines, air conditioners, electric motors, angle grinders, water pumps, electric hoists, etc., the power selected by the generator is generally 2.2-3 times the power of the electrical appliances, because the motor The starting current of induction-like appliances is very high, otherwise the generator may be burned out.
================================

I assume they work on resistive loads only because the frequency is not controlled?
So how do they control the voltage?

The reason I ask is because I'm looking for a DC generator that can supply 30 to 36 volts at 1000 watts.
And I wonder if this unit could be converted to do such a thing ? (Rectifying the wild output after removing the voltage regulator ... if there is one)
Strange little product.
Any ideas?

Veggie

38ac, nothing for me, but thanks kindly for offering. 

veggie

dkmc

Wow ! scary stuff. Thankfully if was caught in time.

take care,
veggie

The speed may be ok for that engine.
Many of the twins run at 1000 rpm.

Ron,

use this for now...   works!
https://microcogen.info.programmertom.com/

Soon to be transferred to the original address. But working well at the moment

Cujet,

Any update?
Also, have you considered running waste vegetable oil ? The fumes are not as offensive.

I know old thread.. Veggie did you make it quiet?  Simpleset and easiest way is mount the exhaust outlet well above a persons ear height.  Maybe two good size mufflers then head the exhaust up side of house 7-10 ft. Works like a charm..  the reason big big generators do it this way.  Outlet above ear height makes a huge difference. No concrete or foam boxes just pipe and mufflers

keith71

Yes, it's super quiet. Have a look at the YTube video links above.
The project turned out very well.
Here...
https://youtu.be/75ffy41BcRY

cheers