Building a pyrography machine

[philippobrien@eircom.net]

I am trying to build a pyrography machine and need some help. I need to know how to convert the ac output from the transformer to dc power.

[Frank S]

A 60 amp mosfet will give you square wave.
I used to just use my Weller 240 w soldering gun with the tip sharpened to a needle point for fine line writing. and various other tips ground to what ever shape I needed like a ball end or a flat spade end
Are you going to re wire the secondary of a microwave transformer for your power supply? If so add a variac ( variable resister) to the primary side of the transformer this will help control the output heat and voltage
Use High temp furnace wire probably 12 or 14 awg for your leads to your pen Use 14 or 16 AWG nicrome for the burn tip

[philippobrien@eircom.net]

Thanks Frank.
I am using a 230v transformer with a 24v 100va output. Di I need to use diodes to convert the power to DC.

[Frank S]

I believe that if I were you. I would first try just connecting a pair of High temp leads to the output then silver braze a bent piece of nicrome wire to them. you can find this in the heating elements of an electric radiant heater. It needs to be silver brazed instead of regular solder due to the high temperatures the tip of the nicrome will develop.
since this will be pure induction current AC voltage will probably be just fine. if not then here is a typical layout of a bridge rectifier

you would size it up or down according to your requirements

[philippobrien@eircom.net]

Frank,
Thanks for your help. I have ordered a variable potentiometer from China so when I receive that I will be putting things together and I will let you know how I get on. I will definitely be seeking your help if I encounter any problems.
Regards
Philip O'Brien