flux-shunt transformer

[Sblanc]

Hi there,
I'm studying to get my electrical licence and on the website the school give as to study there is a picture of this flux-shunt transformer but not more information about.
Anyone knows anything about this type of transformer?
Thanks.

[coppercone2]

A flux shunt means that there is a magnetic element to allow the magnetic force to pass through the shunt rather then through the other core. So if you have a doughnut core with windings on both sides and you put a steel plate in the middle that fits nicely it will be a magnetic shunt (so it turns it into a 8 ), its like putting a resistor across a light bulb in parallel to drop the light output

it holds to the law of parallel resistors but with magnetic force rather then electric current

as you can imagine putting something to change the  series magnetic path resistance of the device is difficult with a fixed core made out of glue and steel but you can always jam something into the hole with little effort to change the magnetic force going through the winding.

[Zero999]

It increases the leakage inductance, therefore the impedance, to limit the current.

[jonpaul]

Bonjour, where are you located? Any link to the website with this image?

The image is a variable shunt neon sign transformer to create a variable current at high voltage  for testing or bombarding neon gas tubes.

In general shunted transformers are used to limit short circuit current, in arc lamps, neon signs, and microwave ovens.

Special laminations are used in production with a fixed shunt built in, or a separate lamination bar is inserted after winding after the other laminations are assembled.

As the lighting industry migrates from ancient arc lamps and gas tubes to modem LEDS these are used less and less.

microwave ovens also have evolved from a HV shunt mains transformer and diode to  a modern SMPS inverter.

Thus these are more of historical interest, but still a very fine magnetic circuit example.

Bon chance,

Jon

[Uunoctium]

may be from here:
https://electricalacademia.com/transformer/special-transformers-applications/
( bottom, last picture )

And don't believe what they wrote about it!
THIS IS NOT A WELDING TRANSFORMER!

Connecting welding cables to it qualifies for 1st prize at the Darwin Award