It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillator, ...

I needed a pulsating light for a certain signaling. Voltage was 230V. So I decided to make a simple circuit, consisted of a LED diode, two capacitors, two resistors, a diac and a diode. Activity of ...

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 ...