Hi Guys,
Sorry for the late reply, been a bit poorly the last few days.
Alec, I probably could use your design and the light may well be helpful at times!
What I would need though is an off switch built in too, as I will be using the circuit to both turn on and off the sander. I reckon a N/C switch in the relays coil line would do the trick nicely though and I have some!
I may have caused some confusion about the original thread name as I didn't know the correct terminology for the setup. Some of my other workshop machines, table saw and router table have this setup and they just have a green on button and a red stop one, but as I said earlier it also serves to make sure the machine does not start when plugged in UNTIL the start button is pressed.
These switches are really handy as I once while at work saw a mate plug in an industrial side wheel grinder which is a bit like a stihl saw, and it was already turned on! WOW did it go! Robot wars had nothing on how that bugger moved, sparks and mayhem followed until it eventually cut its own cable, luckily before anyone got in its way.
Thats one good reason for the switch I'm trying to make.
I also realise that it would be a lot simpler with a mains voltage coil AC relay, but I have loads of DC relays and money is tight, hence making the sander in the first place, which in total has cost me about £20 instead of the £160 at the cheapest place I found (Machine Mart).
Anyway thanks for all the help.
Just one final question. What would be the maximum current available to the relay coil with the components shown? I have a pretty large 24v DC DPCO relay in mind. Its a Schrack RMB05024 rated 25A at 250v AC and the coil looks pretty meaty.
Thanks again Al