With Instructables you can share what you make with the world, and tap into an ever-growing community of creative experts.
Here's a really simple and inexpensive ($1) LED driver circuit. The circuit is a "constant current source", which means that it keeps the LED brightness constant no matter ...
Circuit parts (refer to the schematic diagram)R1: approximately 100k-ohm resistor (such as: Yageo CFR-25JB series)R3: current set resistor - see belowQ1: small NPN transistor (such as: Fairchild 2N5088BU)Q2: ...
Here i'll explain how the circuit works, and what the maximum limits are, you can skip this if you want. Specifications: input voltage: 2V to 18V output voltage: ...
connect leads to the LED
this circuit is so simple, i'm going to build it without a circuit board. i'll just connect the leads of the parts in mid-air! but you can use ...
now we'll start connecting Q1. first, glue Q1 upside-down to the front of Q2 so that it is easier to work with. this has the added benefit that ...
- solder resistor one leg of resistor R1 to that dangling LED-plus wire - solder the other leg of R1 to pin 1 of Q2. - attach the ...
- glue R3 to the side of Q2 so it stays in place. - connect one lead of R3 to pin 3 of Q2 - connect the other ...
now connect the negative wire from the power source to pin 1 of Q1. you're done! we'll make it less flimsy in the next step.
now test the circuit by applying power. assuming it works, we just need to make it durable. an easy way is to put a large blob of silicone ...
Fun with transistorsby Geek07Boy
Simple Led driver/Constant-current source 20 mAby Jan_Henrik
Dimming an LED lamp with an Arduinoby rotormind
Mood vaseby meseta
Simple Power LED Linear Current Regulator, Revised & Clarifiedby KDS4444
Join 2 million + to receive instant inspiration in your inbox.
Download our apps!
© 2015 Autodesk, Inc.
Enter the email associated with your account and we will send you your username and a temporary password.
Not a member? Sign Up »
Already a member? Login »
That's a pro feature!
Want to go pro?
First step is to sign up.
By clicking "Sign me up!" you are indicating that you have read and agree to the Terms of service.
Already a member?" Login »