I bought a Neon Sign Transformer over OKorder and for a while it worked great. I used it to power a Jacobs Ladder (I wired the transformer straight to the Jacobs ladder). However, now the transformer will turn on the jacobs ladder but after a couple of seconds it will shut off and sometimes make a buzzing noise. What is wrong with it and how can I fix it?
It sounds like your transformer is shot and your chances of repairing it are pretty low. You may have been overloading it and burnt an internal connection. Do you have access to a good ohmmeter? Check the resistance, L1 to L2 and H1 to H2, preferably when it's warm like right after it's stopped working. The high side should be several times higher than the line side. Unless you are really sure you know what you are doing don't even try to repair it. The high side is putting out 8 to 10 KV and if your repair isn't up to it you can bet it will leave a mark.
You have 2 problems there. 1. Voltage; 2. Frequency. In this case, both are against you. NZ has 50Hz mains frequency at 240V. If you are really lucky, the transformer will have dual windings on the primary, or a 220/240V. tap. If you don't know what you are doing, consult an electrician or electronics tech. to have them check whether it is dual voltage, and change it. The frequency difference can mean a little less efficiency, the transformer may get a little warmer in operation. But it should be fine. You only other options are to replace the transformer (get one for dual voltages?), or use a 240/110V stepdown transformer ahead of it. The stepdown transformer must have a sufficient power rating for the job.
