Fading LED by LM358

This circuit uses op-amps to obtain a triangle wave. The triangle wave causes the Led to slowly get brighter and then slowly get dimmer until it isn’t producing any light. It then gets slowly brighter again. With the components shown each cycle takes about 4 seconds. The capacitor and the 4.7M resistor are the timing components. The circuit works best when a high brightness Led is used.

Classic LED Flasher Circuit

This LED flasher circuit is a classic two transistor flip flop. This flasher circuit is very popular and it’s usually the first circuit to build when starting electronic circuit building hobby. Here is the schematic diagram of the famous LED flasher circuit: