Parts list

This is a list of everything which I used in my prototype so if you decide against incorporating the "Period" switch then, obviously, you don't buy the switch, just decide on what fixed period you want and buy the appropriate electrolytic capacitors. If you don't want the "Override" switch then you can save on that switch and the red LED.

I used the mains cables from the old mechanical simmer stat as they were campatible with the connections to the boiler element; you might have to buy suitable mains wire, plugs and sockets. I also used a spare bit of old mains cable for the connection to the bench power supply.