# Random Red-Green Light Circuit

#### ngn33r

Joined Mar 8, 2006
2
Hi,

This is my first post. I'm trying to build a simple red-green light circuit found at some airports. All I need it to do is to turn on a red or green light at random when a button is pressed. I've taken some basic electronics courses and built simple circuits, but I don't want to get too complicated with this.

#### Ron H

Joined Apr 14, 2005
7,014
If you take the circuit I designed here and substitute a switch for the oscillator, it should do what you want. Connect one side of the switch where the oscillator was connected, and the other side to GND. Add a 2.2k pullup resistor from the switch to +9V. You might get some switch bounce, but it shouldn't matter. If it's a problem (maybe when you release the switch), let me know here and I'll show you how to fix it.

#### windoze killa

Joined Feb 23, 2006
605
Originally posted by Ron H@Mar 9 2006, 09:11 AM
If you take the circuit I designed here and substitute a switch for the oscillator, it should do what you want. Connect one side of the switch where the oscillator was connected, and the other side to GND. Add a 2.2k pullup resistor from the switch to +9V. You might get some switch bounce, but it shouldn't matter. If it's a problem (maybe when you release the switch), let me know here and I'll show you how to fix it.
[post=14788]Quoted post[/post]​
Good circuit. I might use this one myself.

But what random Red/Green lights at the airports?? I have never seen them or at least noticed them.

#### ngn33r

Joined Mar 8, 2006
2
Originally posted by Ron H@Mar 8 2006, 05:11 PM
If you take the circuit I designed here and substitute a switch for the oscillator, it should do what you want. Connect one side of the switch where the oscillator was connected, and the other side to GND. Add a 2.2k pullup resistor from the switch to +9V. You might get some switch bounce, but it shouldn't matter. If it's a problem (maybe when you release the switch), let me know here and I'll show you how to fix it.
[post=14788]Quoted post[/post]​

Thanks for the help Ron, i'll let you know if i need more guidance.