Sciencemadness Discussion Board - Neon sign transformer circuit

Neon sign transformer circuit

Kloberth - 29-3-2024 at 01:08

Well I know its the wrong forum here but every other forum has not respomded to my question so ill try it here.
I have a Solid state chinese neon sign transformer and I am trying to remove the ground fault protection from it has anyone experiece with such transformers or do i need to trace back the circuit?

Kloberth - 29-3-2024 at 01:53

After looking further at the circuit it is a zvs circuit driving a flyback. Just need to figure out what on this is responsible for ground fault protection

[Edited on 29-3-2024 by Kloberth]

Rainwater - 29-3-2024 at 02:32

I would advise against running the circuit without the potting material, at those voltages arcs can form within 1/2in(14mm) or more

To help, we will need a schematic or netlist. There are many different topologies that can produce ground fault detection.
For that small of a driver, im betting on a dual "current mirror" acting as a different pair. Anytime the dif pair is not zero, you have a ground fault.

Another common but less accurate method is to wind a untapped transformer to your output.
By winding both output leads together in opposite directions, their currents cancel out. The secondary only produces a current under unbalanced load conditions

Screenshot_20240329_063239_Samsung Internet.jpg - 79kB

Mateo_swe - 7-6-2024 at 03:23

I would recommend getting an old style neonsign transformer, they are much more roboust.
I went to an Neos-sign company and asked if they had any old transformers i could get for free.
They of cause asked what i would do with it and i explaned my tesla coil experiments and that seemed to spark their interest.
I got several old style neonsign transformers from them and i probably could have got as many as i could carry, they had a whole pile of them.
I could give one away if you could pick it up but i suspect the shipping is costly as these have a big weight.

PonderosaP - 3-9-2024 at 21:01

OP probably moved on from this year old project but if not:

Quote: Originally posted by Mateo_swe

I would recommend getting an old style neonsign transformer, they are much more roboust.
I went to an Neos-sign company and asked if they had any old transformers i could get for free.
They of cause asked what i would do with it and i explaned my tesla coil experiments and that seemed to spark their interest.
I got several old style neonsign transformers from them and i probably could have got as many as i could carry, they had a whole pile of them.
I could give one away if you could pick it up but i suspect the shipping is costly as these have a big weight.

This, raid a sign shop's dumpster.

If you really want to keep putzing arrund with your chinesium then eliminate the circuit board and hook up the transformer. Connect the appropriate primary winding OCPD for the expected secondary load/ratimg of your transformer and plug that shit into a brand new GFCI outlet. Splice the secindary on to old spark plig wires and run that to your load.

*note you should absolutely not do this unless your a "competent person" with appropriate equipment and procedure to utilize high voltage. Any voltage can be fatal but high voltage of KV+ is especially dangerous because it can easily overcome the inherint resistance of your body.