That transistor one looks not too bad but not as Efficient as the Fet one I posted. Also No Transient Protection.
Strange Note about the collectors tied together: "to Prevent Heating"?
It is a Darlington circuit for Higher Transistor Gain, what has it to do with heating?
Additionally Paralleled output transistors should have a small resistor in each emitter path to offset for small differences in these transistors. Or else one may draw considerably more current than the other, causing failure.
Transformer info would also be helpful for the amateur. 500 watt will require a pretty Big Transformer.
Thanks a lot, I checked both ideas and thanks.
So, just to double check, will these be suitable to use in a car?
By the way Chemelec, have you considered another host for your site, or will you take your site offline if you get shut down?
Additionally Paralleled output transistors should have a small resistor in each emitter path to offset for small differences in these transistors. Or else one may draw considerably more current than the other, causing failure.
I agree, it's not a practical circuit, it's not a question of "one may draw more current", it's more that "one WILL draw more current" - causing overheating and rapid failure.
Also, I doubt 4x2N3055's could handle a 500W inverter, it's pushing things very, very hard.
Hi Clyd3, If I get Shut down, it will depend on what else I can find. I also have a site on Freeweb.com, but unless you Pay, it only allows one
up-load at a time. Good Site but Slow to upload that way.
Geocities is Not an option as I hate Pop-ups.
My Unit works Very Well in a car.
For 500 watts, I definately recommend a Modified Microwave transformer.
I don’t say this circuit is the perfect choice but I don’t agree with you on the emitter resistors. Paralleled transistors fully saturated (almost no voltage across) will not need emitter resistors.