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Mini charger 1.5vdc to 400vac

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Active Member
Hi wasssup,

I had a look at this item.
Its only a one transistor oscillator
using a small transformer.

The circuit you use would depend on the
transformer connections and windings.

The resistor you use would depend on
the transistor, and the circuit.

It is not a powerful unit.
Maybe 2 watts max.

The circuit would be similar to the

If you get a small transformer that you
think is a likely one, post here, and
someone will tell you how check if it
will do what you want.




New Member
WHAT :? I'm not understanding this. How do you put DC in and get AC out. So that is a 1-266 step up transformer :? What is he using that transistor for :? Surely it isn't pulsating the DC :?

Totally confused.


Active Member
Hi herbymcduff,

Well, yes, in a manner of speaking, it is pulsating.
when you feed the output back to the input,
the transistor bounces around, its output is driving
its input, its called positive feed back.

Thats about as non-technical as i can get.

Oscillators are a study in themselves, there are many

The winding with many turns would give the
step-up output, if the circuit doesn't self-excite
then try reversing either the winding in the collector
path, or the winding in the base path.
The feed back has to be 'in phase' with the output
to cause oscillation.

I hope my explanation has not left you more confused.

Regards, John


Active Member
I think this circuit can`t work as oscillator. My opinion: for oscillator need minimum one capacitor.


Active Member
Yes, if you want to determine the frequency.
But there's always some capacitance between components.
I guess that would run at about 12k/c,
maybe higher, depends on the transformer.

Its difficult to say what the circuit actually is,
but its something like that.
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