[Rene Nuñez Paz]

Hello every one
Iam beggining a small cnc foam cutting machine
Cutting area 40” x 30”
Wire lenght max 35”

The machine body and cnc moving is not a big problem,
I have built some cnc routers and this part is fine.

I have Nichrome wire Rene 41 cal 27, from Jacobs,
4.02 Ohm/foot

I need help to select the power supply for heat rhe
Wire.
In jacobs online calculator for that single wire lenght
Transformer Should be 25v and 2.6 A.

I have some transformers, but I don’t know wich one
I can use.

1- A Power Electric RT-625A transformer
I think it was from an old Back UPS.

2- Switching Power Supply .
HSTNS- PD02
Mod- DPS-700CB A
Output 775 W -12V 64.5A

3- A small welding stick machine that gives
Arpund 30V and can hold 200A

4- A complete APC 500 Back UPS
without the battery

For different wire lenght
I think to build a voltage regulator
using a Triac 600V 35A.

Can you help me to select the right transformer

Thanks in advance for read and help me
Sorry my bad english

[Furze]

I have made one of those before and would suggest something like this to control the power going to the wire. It is basically an industrial dimmer switch and could possibly work without a transformer. Crydom may have products better suited to your particular application. This will get you pointed in the right direction at least. Come to think of it, you might try using a dimmer switch if you can get the wire hot enough with the 1 amp or so that they are rated for.
Good luck
http://www.crydom.com/en/products/ca...al-control.pdf