3 LED flasher circuit using astable multivibrator - ElecCircuit.com

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Astable Multivibrator Using BJTs

SOLVED: 3. Build an Astable Multivibrator Circuit with Transistors In this circuit, we will show how to build an astable multivibrator circuit using transistors. By definition, an astable circuit is one that oscillates between 2 states: HIGH and LOW, over and over again, indefinitely. It never holds one state. It constantly cycles from HIGH to LOW, HIGH to LOW, repeatedly. Therefore, it produces a square waveform signal as output.

Op-amp Tutorial 3 : Astable multivibrator, negative feedback