An astable circuit (as opposed to a bistable circuit)
is not stable in any of its 2 states - continually switching from one
state to the other (oscillation).
A circuit that oscillates at a frequency of over 100 Hz can be used to
generate audio-frequency signals. Slower frequencies are used to drive
flashing lights or buzzers.
The interactive example on the right is made from 4 resistors, 2 capacitors
and 2 transistors. With power on, the circuit will oscillate between its
2 unstable states, as the charging of each capacitor turns its associated
transistor on, and the other transistor off.
Using the integrated digital multimeter
and oscilloscopes on the left of the screen, circuit operation can be
demonstrated or observed. The instructor or the student is also provided
with the flexibility of running the simulation in various modes, such
as Key Event Mode, which automatically pauses the simulation whenever
events designated as key events occur.
You can purchase this product online now by visiting our products
list or, for more information, contact
A simulation of an astable circuit.