50Hz with N mosfet : ltSpice transformer problem

j4e8a16n

Joined May 1, 2013
44
Hi everyone,

I made this LTSpice file for testing this 50Hz oscillator inverter

I found a transistor model but I dont see why it does not output a wave.

I used the following formula for the frequency = 1/( .7 * Rbase *C)
Regards,

JPD

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ericgibbs

Joined Jan 29, 2010
14,651
hi j,
Couple of points, the MOSFET Gates are floating [now connected] , also it needs a kick to start it, ie: the .IC condition.
E

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Alec_t

Joined Sep 17, 2013
12,448
...... also note that the 2N222s will fry because the negative-going voltage on their bases exceeds the base-emitter junction breakdown voltage.

j4e8a16n

Joined May 1, 2013
44
...... also note that the 2N222s will fry because the negative-going voltage on their bases exceeds the base-emitter junction breakdown voltage.

??? Is there a solution?

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ericgibbs

Joined Jan 29, 2010
14,651
hi j,
It is usual to fit clamp diodes from the Bases to 0v, so the Vbe reverse does not exceed -0.7v
But this may effect the osc frequency, it is a poor design.
E

Alec_t

Joined Sep 17, 2013
12,448
It is usual to fit clamp diodes from the Bases to 0v, so the Vbe reverse does not exceed -0.7v
Alternatively, a diode in series with the base input will protect the base-emitter junction.

Bordodynov

Joined May 20, 2015
2,948
Note the drain voltage and current

j4e8a16n

Joined May 1, 2013
44
What are the values for L4 L5 L6 ?

Bordodynov

Joined May 20, 2015
2,948
Modeling the effect of magnetic fields on inductance.
The values of L1 and L2 are calculated in param.