LED Tester with Regulated Current

Overview

The use of current regulator in a LED tester is shown in this project which will allow determining the exact voltage and current to supply a LED.

Explanation

Testing a LED comes in two ways. First is by plugging it into the female header where the anode is the top hole and cathode is the bottom hole. Second way is by using the magnetic SMD adapter where the LED terminals are placed on the adapter. The SMD adapter is designed for testing SMD LEDs but can work with regular diodes.

The tester was designed for convenience of measuring the voltage and current by either using the test pads or the test loops. The top test pad/loop is used for measuring the voltage and the bottom test pad/loop is for measuring current while the middle test pad/loop is common. The shorting block should be removed when measuring current. The jumper was placed between the middle and bottom test pads/loop for intuitive purposes.

In testing a LED without specifications, it is hooked up to a multimeter to measure the current before removing the shorting block. The LED is placed on tester and the trimpot is adjusted.