[mircemk] built a slick-looking LED tester with a couple handy functions built in. Not only can one select a target current to put through an LED, but by providing a target voltage, the system will ...

Light-emitting diodes (LEDs) are often used with a voltage source from a power-supply output voltage. The output voltage increases until the current through the LEDs reaches the value of the ...

The basic circuit illuminates up to ten LEDs in sequence, following the rhythm of music or speech picked-up by a small microphone. The expanded version can drive up to ten strips, formed by up to five ...

Editors’ Note: This segment is adapted from Chapter 3 of Power Supplies for LED Driving by Steve Winder. We have seen in Chapter 2 that an LED behaves like a constant voltage load with low equivalent ...

Lighting a string of LEDs at a constant brightness requires driving it with a regulated current. A boost converter is commonly used to step up the voltage to a level high enough to bias the LEDs on ...

Microcontroller port pins can typically be driven either high or low, or else be put into an "input" or high-impedance state. This circuit uses the three states to drive two separate LEDs with one ...