Electronic Timer

Most of the timing circuits using a capacitor's charge or discharge rate we've built so far have been relatively simple.

This is a more complex Project which is more like actual timing circuits used in electronic devices. Before you finish the wiring, set the Select Switch to B.

When you finish the wiring, let the Select Switch remain at B for a few seconds. Then move the Select Switch to A. The Lamp will come on for a few seconds and then go off. Does it stay on longer if you let the Select Switch remain at B for more than a few seconds?

You might want to try replacing the 3.3 uF capacitor with a 100uF one and see what happens (be sure to get the + connection right!).

What do you think will happen now ?

You might try adding other capacitors in series and parallel and seeing what effect they have on circuit performance. Be sure to keep notes of what happens, do you see any patterns in the results ?