LT_spice bistable oscillator base on inductance

Thread Starter

Jérémaguila

Joined Mar 9, 2023
8
Dear all,
I'm currently trying to simulate another oscillator based on the circuit below where the MI (magneto inductance) are represented by an inductance and a resistance in series. I think this kind of circuit is part of the bistable oscillator family. The purpose of this oscillator would be to link the value of the inductance with the oscillation frequency of the circuit.
1679998084964.png
I tried to model this oscillator in Ltspice but there are no oscillation.
1679998400540.png

Maybe it's due to the fact that I used bipolar transistor and not CMOS? Or I should use a pulse to make the oscillation start?

Thanks in advance for your help
Kind regards
Jérémie
 

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Thread Starter

Jérémaguila

Joined Mar 9, 2023
8
Get rid of the 1k emitter resistors and the circuit then oscillates, albeit with low amplitude.
Thanks a lot for your answer and your time, I tried removing the 1k emmiter resistance but it's still not working. Moreover in the circuit the output is the tension at the born of these resistance. Is it not an issue?
 

Audioguru again

Joined Oct 21, 2019
6,782
My transistor multivibrators do not have emitter resistors therefore they have enough gain to oscillate. Your 1k emitter resistors reduce the transistor voltage gain to almost mothing.

My simulated transistor multivibrator circuits are stated with a "startup" command since a simulation has no circuit noise to start the oscillation.

Make it like this:
 

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Thread Starter

Jérémaguila

Joined Mar 9, 2023
8
Thanks everyone for all of your answer. I'v tried them and it's oscillating now. Do you think this type of oscillator could go up to MHz frequency?
 
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