Grab the datasheet for your LEDs and open Circuit Playground... find the values for 'Forward Voltage' and 'Forward Current.' 

Plug-em' in, and voila!

It looks like the LEDs I selected require a 1/8 watt 180 Ohm resistor to prevent the battery from over-driving the LEDs and burning them out.

 

There can be a little variance in the resistor value... +/- 10% shouldn't be a problem. 

Just remeber to enter 3x for the Series LED Count!

You can even free-wire the circuit if you want... my prototype may be ugly, but it works a treat!

I sealed the prototype in epoxy to prevent the connectors from wiggling around. Some of the epoxy ran through the holes in the clip... next time I'll plug those with a bit of hot-glue.

This guide was first published on Oct 06, 2014. It was last updated on Oct 06, 2014.

This page (Datasheet... to prototype) was last updated on Sep 29, 2021.

Text editor powered by tinymce.