A: Hey Woz - whatcha doin?

W: Oh hi Adabot - I was just adding some power protection to this circuit

A: Interesting - why does the circuit need to be protected?

W: Well a circuit needs to be protected for a couple of reasons.  One example is if I was to connect a battery to this incorrectly then electrical current might flow in the wrong direction and damage some of the components.

A: Oh - how do you make sure that doesn’t happen?

W: Well, we use a diode! 

W: By placing a diode at the circuit’s power input we ensure that current will only flow in one direction - the correct direction that we’ve designed the circuit to work with.

A: So - a diode is like a one way street for electrons?

W: Exactly - the electrons can only flow through the diode in one direction and they have a really hard time going back the other way.

W: The stripe indicates which end of the diode acts like a wall to block the electrons.

A: Diode!  Protector of circuits!

W: Yes, but diodes do more than just protect circuits, Adabot.

A: Oh?  What else do they do?

W: Some diodes emit light when we pass current through them.  We like to call these “light emitting diodes” or L-E-Ds for short.  Maybe you’ve heard of them?

A: LEDs? I love LEDs!!

W: I thought so!

A: So that’s what “D” stands for in LED.  D is for - Diode!

W: That’s right.

W: Well, looks like this circuit’s all done - how about we go test it out?

W: Adabot - are you coming?

A: Sorry Woz - I’m an electron in a diode - I only go in one direction!

A:  Ow … Ow …

W: Oh Adabot, let’s go.

This guide was first published on Dec 19, 2014. It was last updated on Dec 19, 2014.

This page (Transcript) was last updated on Sep 29, 2021.

Text editor powered by tinymce.