Simple Transistor oscillator

441

14:22:23

Quite a neat little circuit, found online. Im thinking the way that it works is by biasing the first NPN into the capacitor, it is then pushing the emitter voltage of the transistor up to increase its collector voltage turning on the second NPN, which boosts the cap, once the cap has discharged enough the voltage rises at the emitter of the first NPN to start the cycle again. 

published 8 years ago

BillyT

8 years ago

Nice little circuit, you are probably right about its function, it's so stable while also being so very adjustable, change the capacitor or resistors and it doesn't miss a beat, 10 - 47uf to see it in real time.

Jalaj

8 years ago

Its called Astable-Multivibrator circuit. Most blinking LED applications use this kind of circuits.

thebugger

8 years ago

It's a little different than a typical astable multivibrator. Firstly the stages are galvanically connected and the input and output is taken between the emitters, forming a sort of bootstrap positive feedback. Usually the output is taken at the second collector and the input is taken at the first baae. This is more close to a sort of a self oscillating schmitt trigger or something

faceblast

8 years ago

what's the source

emogenet

8 years ago

Isn't that the oscillator shown in w2aew's latest vid ?

emogenet

8 years ago

Yeah, it is : http://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/

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