Electronics: 555 Timer as an Astable Multivibrator

By Cathleen Shamieh

Part of Electronics For Dummies Cheat Sheet

The 555 can behave as an astable multivibrator, or oscillator. By connecting components to the chip in your electronics, you can configure the 555 to produce a continuous series of voltage pulses that automatically alternate between low (0 volts) and high (the positive supply voltage, VCC).

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You can calculate the low and high timing intervals using the formulas that follow:

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