Thread: Controlling amperage

It depends on the type, gauge and length of the wire. Different wires have different resistance.

Here is a link that may give some clues

Nichrome wire and transformer selection

An electric train controller or any rheostat will do that.

Should be easy you mean like this one

Styrofoam HOT Wire Cutter Block Sheet Foam Craft 48 BOW Only Cuts Fast Straight | eBay

I used to have one similar many years ago cant remember if you could vary the power though

EDIT: here is a variable controller will do what you want but costs a bit more
http://www.ebay.com.au/itm/1Metre-Ho...item2c74892132

Many moons ago my father would use the element from an old bar heater as a rheostat for controlling current on his battery charger when charging small batteries.
One end of the element was connected to the battery, and the lead from the charger had a large alligator clamp on it. You simply moved the clamp along the heater element until you got the correct current, then clamped it on.

Something like this is a bit more modern 12VDC 8A Dimmer / Motor Speed Controller - Jaycar Electronics

First bit of info you need is how much current does it take to get the wire to the correct temp for cutting. Once you know that, you can choose a controller with a suitable current rating. No point paying for a 20A controller if you only need 3A.

Steve

would it be possible to use a soldering iron thermostat?

When I made mine I just hooked a motorcycle battery straight up to it, worked a treat.

Cheers
Will

thanks all, the jaycar one looks nice, will give it a go and post back the results.

Made one years ago, and hooked it up to a battery charger I built as an apprentice. I found the 6 volt high setting worked well, but no idea really of what that was - never measured the volts or amps.