In this circuit, you’re going to build a touch sensor. You’ll create a touch-pad from two uninsulated wires. If you don’t have any wire, you could clip off a bit of the legs of one of the components.

These are the names of the transistor pins:

• Top pin: Collector
• Bottom pin: Emitter
• Left pin: Base

Note that if you are using a different transistor than the BC547, the pins may be arranged differently.

Here’s a video of the version I built. I needed to wet my finger bit to get the LED to turn on:

The Circuit Diagram

Find the components used in the table below.

Are You Stuck?

Let me know your questions and comments in the comment field below