Quote Originally Posted by mike_biddell View Post
peachy555-1.jpghere's the 555 light toggle switch. Just substitute a FET of your choice and the valve as load on pin 3 in place of the 2n2222. This circuit also works well in the simulator. Unfortunately the allowed file sizes are rather small. so it's only just legible. Compared with the first circuit, it's completely analogue.
Oh, forgot to say, to allow light threshold switch point tweaking on the first transistor, change the fixed 10k (R1) to a pot.