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 ...

This circuit is not complex, but it saved the day in an application involving visual inspection of the spray pattern of fuel injectors for quality and consistency. In this application, xenon strobe ...

This is a simple blinking led circuit powered from 220V that can be used to mark special places or as voltage indicator. The voltage from the mains charges the capacitor through R1 resistor and D1 ...

Photos of a transparent LED screen with a “ZJU” pattern on toughened glass, emitting different colours under corresponding biases. (Courtesy: Liu Yang, Zhejiang University) Researchers in China have ...