Help with transformer

Question

hello world,

i am working on a hot wire foam cutter and have used an old wall wart transformer. i took off the top coil (secondary) and replaced it with thick solid gauge wire with 3 turns. i then put a piece of steel wire onto a frame and wired it up. will this work or will i blow the house?

thank you michael.

Former Member · Answer

Hi

Here Transformer calculation - Vypočtěte si trafo | HW.cz you have a calculator, you can check the parameters of the transformer.

Normally transformers can work with momentary overload but you have to be careful. I suggest you find out what power was designed and then you can estimate whether you can.

Regards.

jw0752 · Answer

Hi Michael You will not blow the house but it will probably not work. First of all be careful as even with a wall wart the line voltage is close by and dangerous. Check the V A of the transformer. This is a good approximation of how much power is available. If there is not enough power it will not heat up your cutter. You can check the voltage of your secondary when it is under load and measure the current through it. Multiply the amps times the volts to get the watts. The limiting factor is the resistance of the primary as this will limit the current and thus the power available from the primary. As we all know you don't get something for nothing. I just checked a wall wart that I had handy and found that the primary could consume 30 watts while the seconday was only able to provide 5 watts. The rest is lost as heat in the inefficiencies of the transformer's internal resistance and coupling.Good luck and be careful.

John