Help with blown transformer

[kingnitro1]

Hello,
I have a blown transformer in a Russian night vision scope. It has no markings on it any where. The battery voltage is 2.5 volts. It looks like the output voltage of the circuit is 400 volts. Any way of finding a replacement transformer? Attached is the schematic.

 

[Jon Wilder]

Without having any specs whatsoever on that transformer, it's not going to be cheap. Your best bet is to get with a company that winds custom transformers. You would send them the blown transformer, where they would have to tear it apart wind by wind and "reverse engineer" the blown one, then reassemble it to spec with new windings and possibly a new bobbin if the one in there currently is burnt/melted.

A couple of companies you may want to get in touch with are -

Heyboer Transformers
Heyboer Transformer - Top
(616) 842-5830

Magnetic Components
Magnetic Components, Inc. Home Page
847-671-0633

I've done business with both of these companies and they're both great to deal with. Heyboer has VERY reasonable pricing although I couldn't tell you how much they'd charge to rewind your stock transformer so you'll have to give them a call for a quote on that.

 

[gary350]

I have rewound many transformers. Take it apart. Unwind each coil take note write it all on paper. Mic the wire if it is burnt it will measure .001" small. Buy new wire at a motor rewind shop. Hand wind it and varnish each layer with polyurethane varnish and let it dry before doing the next layer. The hardest part may be finding the material that goes between each layer of wire the motor rewind shop may have that. After the transformer is finished paint the metal lamination with varnish too this keep it from vibrating. Transformer is an easy fix its just a little slow. I use to work in a transformer factory they do not always varnish each winding if they did there would be a lot less self distruction from wire vibration. Motor rewind shops have white fiberglass tape it works great between each winding. I have also use cerial box cardboard between the winding but it is pretty think and takes up a lot of space.