Am trying to hack together a set up to power a wood burning pen.
The set up is similar to a hot wire power supply. Just a light dimmer switch and a transformer.
After a little playing I managed to get it to put out the right amount of power to heat the pen tip to red hot and able to burn wood, leather...
The problem I now have is that after a few minutes the transformer starts to heat up and I get that lovely "electrical stuff burning" smell.
I am about to give up and just buy the right supply, but before I do, just wondering if there is anything obvious I am missing.
Some of the details:
The dimmer needed a little adjustment to get the output from the transformer down to about 4-6 volts. I've replaced the 150K trim pot with a 330K resistor.
The transformer was originally set to put out bout 24V ac. and I've taken 15 turns off the output winding. Output voltage at full power is down to 19.5
I can lower this to less than 1 volt using the dimmer.
The winding resistance is about .3 ohms and that is the approximate value of the burning tip resistance.
Before I started hacking the transformer, it had a 4 amp breaker built in. So I assume that it was able to handle about 96 W
I assume that the transformer must dissipate the same about of heat as the burning tip and this should be in the 100 W range.
That doesn't seem to be too much but...
Appreciate any help, ideas...