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A Tiny Homemade
Square Wave Signal Generator ('Dead Bug' Style)

SquarewaveThis page shows you how to make a super simple square wave signal generator. The circuit below uses a 555 timer chip, a capacitor, and some resistors to generate a variable frequency, variable pulse width square wave. The term 'dead bug' refers to the way that the finished circuit resembles a dead insect. This is because the solder connections are made directly to the components and there are legs sticking out making it look much more messy than the diagram below.

This is a very basic circuit and therefore does not produce an ideal square wave over the full frequency range. The pulse width or duty cycle can only be varied by a small amount, and doing so also effects the frequency output.

If you want to try a more advanced and more accurate version see the DIY Signal Generator II

Simple Function Generator

This diagram shows how the circuit can be wired without the need for any circuit board. A 14 pin IC socket is used to hold the main circuit so the 555 chip and the two pots can be simply plugged in. The total parts list is shown below.

14 pin IC Socket
NE555N Timer IC
1k Resistors x2
10k Variable Resistor/ Potentiometer x2
Capacitor selection for C1

If you want to switch loads like coils, motors and lights, our range of Cyber Circuits are for you!

The diagram represents a view from below and is not to scale. The circuit may be a little tricky to solder, but its about as simple as you can get for a signal generator.

This circuit can be used in the DIY Tesla Coil project as part of the Ignition Coil Driver

The value of the capacitor C1 will determine the range of frequencies produced. Somewhere around 0.1 to 0.01 microfarads should be adequate for mid range audio frequencies.

Comments and questions for DIY Signal Generator

The information provided here can not be guaranteed as accurate or correct. Always check with an alternate source before following any suggestions made here.