Intro:
This is a modern take on the original Garner oscillator, unlike other versions this one won’t lock up in full conduction and is guaranteed to always oscillate using modern parts, whereas the original -after a few modifications- would only seem to work with germanium transistors.
Mods:
The modifications are clear, we basically introduced a series resistor to limit inrush current during the low period, the low impedance side formed by the 10 Ohm resistor in Q2’s path was also adjusted, originally a higher resistance was found. We therefore achieved a safe balance which allows us to revive one of Garner’s proudest moments (Hey why else would anyone patent it otherwise, right?)
Another take:
Taking this oscillator as a baseline we can introduce other forms such as a sawtooth oscillator (It’s not perfect though!) with the help of our friend, capacitance.
How to:
To visualize the output waveform you could use a soundcard or a proper oscilloscope. Since the oscillating frequencies on both circuits are within the audible range you could also use a piezo speaker to hear it.
Fun isn’t it?, feel free to experiment and let me know if you find anything intersesting!.
Cheers.
Here’s a scope shot of the “Garner Simple” oscillator in case anyone is interested: https://mlwlc89ilglb.i.optimole.com/w:auto/h:auto/q:mauto/f:avif/http://gushh.net/img/blog/electronics/garner/scope1.jpg
Yes, I do build at least 99% of what I post. Otherwise I would not share the schematics because I could not assure their functionality.
Cheers.