Sometimes you need to know which wire/node is positive polarity and which wire/node is negative polarity.The LED as a polarity indicator circuit is show in above diagram. In the diagram as you can see ...

It may also be used to check a string of LEDs (one at a time) to make sure that all are installed correctly. LED Tester Circuit Schematic simple led tester schematic Why 3V? 3V is sufficient to turn ...

Older designs relied on simple resistors to limit LED drive current, but designing an LED circuit based on the typical forward voltage drop as specified by a manufacturer can lead to overheating of ...

A Simple Over-Voltage Protection Circuit for LED Drivers This boost circuit implements current mode control and senses the LED current via resistor R14. The output voltage is boosted to just over 30V ...