We’re always impressed when a piece of hardware is torn apart, rebuilt and ends up exceeding the capabilities of the original device. [Dave] and [Will]’s home-built TIG welder is no exception to that rule.
When [Dave] and [Will] started working on converting a simple AC stick welder to a welder with every function imaginable, they decided to keep it simple. After looking at some high-price commercial welders they came up with a list of features they wanted to have and decided to implement this in TTL and CMOS logic. The guys didn’t want to go with a microcontroller solution because not everyone can code, and discrete chips are very easy to troubleshoot given minimal tools.
For the high voltage part of the build, the original flyback transformer was replaced with a neon sign transformer and homebrew spark gap and capacitor. The plans for a homebrew spark gap and cap didn’t quite work out so they were replaced with commercial units. The guys included schematics and a PCB layout (PDF warning) of their build. It’s always great to see an amazing logic chip build, and improving an existing tool never hurts.
Thanks to [Franci] for sending this one in.