Current Regulated LED Tester

Step 2 Circuit schematic and layout

Look at the images for the schematic and layout. You can refer to this Instructable for directions on fabricating the PCB. The Instructable uses this circuit as an example so you can directly follow it.

Remember to check the pinout of your regulator

I've also included a PDF of the layout that you can print. DO NOT scale when printing if you want to use the layout as a mask for photolithography or toner transfer.

Comments

[digikawa]

Hi. Isn't there a mistake on the schematic ? The (+) pin of the LED should be on the ADJ pin rather than on the Vout pin, am I right ? On your PCB layout your connections are ok though.

[cinezaster]

Indeed, you have to switch Vout with ADJ.
The Anode of the led must be connected with the ADJ. Connected like this it doesn't work. You burn out your leds. (yes, I learned it the hard way). Your layout is ok.

[adnimo]

 theres a voltage divider comprised of two resistors, by varying the reference voltage the output voltage of the regulator is also changed.

[adnimo]

You do realize almost any DMM in the diode mode will light up most low power LEDs and it's already current limited?.