Ignoramus965 wrote:

My objective is to make a square wave inverter for high amperage DC
for TIG welding, from a 300A CC DC welding power supply.

I would actually be content with 200A current. AC would be used for
aluminum only.

I own a Wavetek 171 signal generator:

http://www.labx.com/v2/spiderdealer2...m?LVid=2779965

It can do up to 10 volts, supposedly, and any frequency.

Can I simply use it to drive either MOSFETs or IGBT's that make up the
H bridge?

thanks

i

I would not use the signal generator because it isn't really optimal for the
job, and if you get for example a drain to gate short in a blown MOSFET,
you will quite likely destroy your Wavetek. Get the National Semiconductor
datasheet for a 555 timer and build yourself an oscillator. This is
seriously just as good for what you are doing, and when it blows up you
will be less upset (or at least I would). If you need to drive MOSFET
gates fast, I recommend TC4421 or TC4422 chips connected after the 555,
they are supposed to put out 9 Amps, which your Wavetek can't do. The 555
can run off a 5V regulator. Keep the wires from the TC4421 to the MOSFET
shorter than 1 inch for low inductance, and put ceramic and electrolytic
decoupling caps right next to each 4421.
Chris