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Project Notes

#234 CMOSInverterOscillator

Use a CD4096 to generate an oscillating waveform and plot the results

Build

Notes

I found this oscillator circuit as part of the LEAP#182 PowerSupply317Kit.

It is another variation of the basic Schmitt Inverter Waveform Generator pattern, which I tested in LEAP#022 SchmittOscillator.

Performance

… is quite terrible actually. Oscillation is only sustained for a small sweep of the 100kΩ pot. The waveform is also heavily asymmetric - with a duty cycle at most 25%.

Setting C1 R1 (pin 2-3) Frequency
max sustained oscillation 10µF 2.5kΩ 27Hz
min sustained oscillation 10µF 40kΩ 0.4Hz
max sustained oscillation 1µF 2.15kΩ 165Hz
min sustained oscillation 1µF 40kΩ 4Hz

Scope trace for C1=1µF, R1(2-3)=2.15kΩ:

1uf_2k

Scope trace for C1=1µF, R1(2-3)=40kΩ:

1uf_40k

Construction

Breadboard

The Schematic

Build

Credits and References

About LEAP#234 CMOSOscillators
Project Source on GitHub Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is my personal collection of electronics projects, usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting (IMHO!).

The projects are usually inspired by things found wild on the net, or ideas from the sources such as:

Feel free to borrow liberally, and if you spot any issues do let me know. See the individual projects for credits where due. There are even now a few projects contributed by others - send your own over in a pull request if you would also like to add to this collection.