@happyvalley808,

Thanks. I'm glad it is working.

I also think that Gmeasts idea of using an insulation transformer is important
to avoid burning the inverters. A transformer can take much more "abuse"
than those flimsy HEXFETs used in most small inverters.

Groundloop.

@Groundloop,

I have limited electronics knowledge, do you think a microwave transformer is overkill or do we need one of this size....

HV

@happyvalley808,

If you use a 110 VAC inverter and needs approx. 40 Watt then use a 110VAC to 110VAC 40 Watt transformer.
Connect the inverter to one of the transformer pairs, connect plasma circuit to the other pair. (For 230VAC you must use a 230VAC to 230VAC transformer.) You still need a series coil on the plasma circuit! See drawing.

What you are doing is insulating the inverter from the plasma circuit.

Groundloop.

modified circuit

Quote from: insane4evr on September 18, 2008, 12:03:47 AM
Hi Luc,
Thanks for this find. I am jumping on this sparkplug testing because of yours and others posts, so I also bought one. I hope I get it soon here in usa.

Just got the 12vdc to 240vac inverter I ordered and examined it.

It seems that most of them are basically DC to DC converters. The DC output is converted to modified sine-wave using mosfets as Groundloop says.

Since the plasma circuit rectifies this AC back to DC, I think that you can do away with the rectifier and tap directly to the DC output of the inverter. The output DC section of what I got measures 257 VDC. The one I have has its output isolated from its input and I think most inverters are also isolated.

More work to do.