Two-LED Winker
Électronique / Electronic
NE5532

The LED circuits in Projects (Operational Amplifier "Winking LED" and "LED Flashing Light," respectively) each use one LED, but the circuit in this project uses two LEDs that take turns lighting.

Slide the switch to position OFF and assemble the circuit.

Then turn the power on by sliding the switch to position ON and wait for a few seconds. The LEDs light and turn off alternately. The dual operational amplifier works as an astable multivibrator as in previous projects.

When the output is high, LED 1 lights, when it is low, LED 2 lights. You can change the speed of the winking by using different values for R2 and C1. See how the speed of the pulses changes when you change the value of R to 220K ohms.