Making a flyback transformer

[The Roberto]

I'm putting together a simple coilgun but want to make the circuitry
easier to see than if I simply pulled the transformer out of a single
use camera. I'm only charging a 300V capacitor, so I don't need the
greatest output (like out of a TV flyback). What can I use for the
core (nail, washer?)? How many turns on the primary and secondary?
Thanks for any input.

Roberto

 

[John Popelish]

The Roberto wrote:

I'm putting together a simple coilgun but want to make the circuitry
easier to see than if I simply pulled the transformer out of a single
use camera. I'm only charging a 300V capacitor, so I don't need the
greatest output (like out of a TV flyback). What can I use for the
core (nail, washer?)? How many turns on the primary and secondary?
Thanks for any input.

Roberto

Ferrite is far superior to any kind of iron material, except, possibly
a silicon laminated transformer core.

You might find some small iron core transformer (preferably a waxed
one) with a plastic bobbin. Pull all the laminations out of the
bobbin, gang all the Es and Is in two stacks and put the Es back into
the rewound bobbin with the Is on top of a paper shim. The gap added
to the core will allow it to store energy and release it efficiently
during the flyback.

A cheap and common ferrite core for such purposes is a two piece bead
that is made to place on a power or signal cable to suppress RF
interference. The two halves need to be assembled with that same
paper shim between the halves ot provide a small gap. You can either
wind each half core first and then glue them together on the shim, or
glue it first and them wind by passing wire through the hole.

--
John Popelish