I'm considering building a pulser circuit for my EconoTig. The front panel jack provides provides an external access point that can be used to pulse the welder on and off or to alternately switch between an amperage programmed on the torch thumbwheel and a setable background amperage.
My goal is to make the welder more friendly and usable to use for butt welding 20 gauge steel, such as auto patch panels. Can anyone who has tinkered with an EconoTig controller board tell me what sort of bandwidth may be available at the front panel control port for pulsing the unit and what sort of pulse rate, duty cycle setting and background current settings would be suitable. The front panel port has an on/off switch and a 1K post that varies amperage from minimum (whatever that is) up to the front panel dial setting which can be as high as 160 amps. It should be a simple matter to configure some cmos analog switches and a multivibrator or two to create a lot of options this older design could benefit from.
I understand the output inductor may be one of the limiting factors for obtaining minimum current settings. It's not clear how running the higher current setting at 50% duty cycle will work out, but I'm hoping it will make heat control more precise when working with thin materials.