[font size="1" color="#FF0000"]LAST EDITED ON Apr-07-01 AT 11:12PM (CDT)[/font][p]Basically all it is is a DPDT relay with a set of switch contacts. Instead of turning on the tool directly, your switch pulls in the relay and it latches on (the 'on' switch is momentary action). If the power goes out the relay drops and you have to hit the 'on' button again to get it to pull in.
The 'off' button is a Normally Closed switch in series with the relay winding. When you hit the momentary 'off' switch the effect is the same as a power off and the relay drops out and stays out.
Hang on a bit and I'll post a schematic... but really it is cheaper to buy...
[font size="1" color="#FF0000"]LAST EDITED ON Apr-08-01 AT 10:52AM (CDT)[/font][p]Habit. Good design tells you to keep your control and high power circuits separate.
Actually the feed to NO2 should be direct from the plug instead of from where shown this is so that the switch contacts do not carry the full load of the device. Cheaper and smaller switches. I've redrawn it to show the correct wiring.