Low frequency square wave oscillator

Thread Starter


Joined Mar 7, 2023
I tried to simulate Beck's circuit and was unable to see the ~4Hz result. There HAS to be an easier circuit than this. Any recommendations?

Moderator edit: new thread created from this.


Joined Oct 2, 2009
Welcome to AAC!

You can build a very versatile square wave oscillator use a 555-timer IC. I would highly recommend that you use a CMOS part such as LMC555, TLC555, ICM7555.


You can also build a simple oscillator with a Schmitt trigger inverter.



Joined Nov 6, 2012
When considering the requirements of a "Building-Block" Circuit,
all of the Inputs and Outputs need to be specified,
or at least a good explanation of what the end-result should be
when incorporated into other described Circuits.

All these questions need to be specified, ( and maybe more ) ..........

What is the purpose of this Oscillator ?
How much Voltage-Output ( Source & Sink ) ?
How much Current-Output ( Source & Sink ) ?
Will the Load be Capacitive or Inductive ?, ( what is the "character" of the Load ) ?
Total Frequency-Range ( from-to ) ?
Does it need to be adjustable ?, ( Frequency, Voltage, Duty-Cycle ) ?
Is the Duty-Cycle required to be precisely 50% ?
What will supply Power to it ?, ( also Single-Supply vs Dual-Polarity-Supply ) ?
Do the switching-edges need to be sharp or soft, and why ?
Frequency-Stability vs Temperature or Load ?
Does it need a Start-Stop Input ?
When stopped, does the Output need to be High, Low, or High-Impedance ?