How to make a simple oscillator with transistor and Capacitor?

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sr13579

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I provided a circuit which should discharge at a specific time. But this circuit is not working as an oscillator. How should I make circuit which will give me oscillation?
 

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I don't know of a way to make an oscillator with a single transistor. But here is an example of a classic two transistor oscillator.

 
The circuit in the first post might work as an oscillator if you replace the transistor with an SCR.
 
There is an oscillator that uses the reverse-biased emitter-base of a transistor that has avalanche breakdown like a Zener diode (the original schematic in this thread has a Zener diode).
Replace the LED with a speaker to hear it.
Change the value of the capacitor to change the frequency.
It will not work if the battery voltage is too low.
 

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G

You may also want to do a Google of "tunnel diode oscillator circuit".

Getting a bit esoteric now aren't we?

It also seems fairly obvious that he's looking at audio oscillators, as far as I can recall (never having even seen one) tunnel diode oscillators were for microwave frequencies.
 
Getting a bit esoteric now aren't we?

It also seems fairly obvious that he's looking at audio oscillators, as far as I can recall (never having even seen one) tunnel diode oscillators were for microwave frequencies.
Actually Nigel the first tunnel diode oscillator I built was as a kid and maybe the early 60s. It actually ran in the 6 meter ham band or about 50 MHz. I do however agree I was on the esoteric side. OK, we will let it go with a unijunction relaxation oscillator.

Ron
 
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