Electronic Jigsaw Puzzle

Here's a test of your ability to read schematics and understand the operation of the Relay and CdS Cell. You've got to figure out for yourself how to get the Lamp to light, because we're not going to tell you.

Actually, figuring out how to get the Lamp to light shouldn't be that big an undertaking ...just turn power ON, after you finish the wiring connections.

Set the Select Switch to A or B and put the CdS Cell in light or darkness. You can find the right combination of these three by trial and error.

But first try to figure out the answer by looking at the schematic. Try understanding this circuit by tracing the path the electricity must follow (and remember that electricity flows from negative to positive).

See where the current path is broken and what must be done to close the circuit again (remember too that the resistance of a CdS Cell increases in darkness). Think you understand how to light the Lamp? Good!

Make a note of your guess, press the Key and, Did it work???