Saturday, August 30, 2014


Just another question on AC or DC power supplies. Seems to be common.

when we say power supply requirement is 12 volt 2 amp .does this mean that we need a power supply to convert 230 volt ac supply to 12 volt dc or ac.

For Nichrome Wire, it doesn’t matter if it is AC or DC. You just want to make sure your power supply has enough power (wattage) to handle the circuit’s current (amperage). I usually tell people that 2 amp is kind of your minimum. If you can find a 4 amp power supply you’ll be able to have a wider range of wire temperatures. 

Also, remember that the voltage is constant and amperage is a function of your wires resistance. So depending on your circuit, and depending on your voltage setting, you may only require 2.5 amps to heat rather than the full power supply’s 4 amps… Just remember voltage is constant, amperage is variable based on wire/circuit resistance

Monday, August 25, 2014

Kanthal Wire

I am interested to know whether it is possible to use round Kanthal 0.32mm wire as opposed to Nichrome wire in a HWFC?

I don’t see why not? My experience is in Nichrome wire and a little in stainless steel. But when building a simple cutter, you only really need a resistance wire and the alloy shouldn’t really matter. 

I have used and recommend NiChrome because its electrical properties are known and easy to calculate. Most of the other alloys have resistance information but not necessarily amperage-to-heat tables. 

Using Ohms law, with a given wire’s resistance you should be able to calculate an amperage based on applied voltage. So you can see if your power supply has enough juice to handle the circuit. 

Aside from that, I did find a website that has some reference data ( here ).  Whenever people ask about novel wire or applications, I always encourage them to give it a try knowing that you can always fall back on nichrome if you need to!

Thank for the quick reply. I have done a lot of research in constructing a HWFC's, and of all the websites and YT videos no one seems to have tried Kanthal. So being a bit of an experimenter, I have ordered some Kanthal from a supplier on eBay.
 Also I would like to use a 12v 6a supply apapter and regulate the dc output (as opposed to regulating  the ac input) with a high amperage dimmer switch that I also saw on eBay.... similar to eBay item number  191295309081 
Thanks for the the info from your website, it has been most useful.
Perhaps I will make a video of the HWFC I build and post it on YT.
Yes, I will let you know the outcome of using Kanthal when I finish constructing my HWFC.

All that sounds great, I don’t have any additional input just some thoughts.  

In general, you never really want to dim the primary side (AC input) of a transformer. Especially if it is an AC-to-DC power supply. It can have unreliable but also potentially adverse effects on the electrical set up. Even with your AC step down transformers (AC-AC) you want to dim the secondary windings (output side) of the power supply. 

As for that DC dimmer, that is cheap! I’ll have to save that information. I had a user email me some information on a DC dimmer, but they were hard to find. I don’t know why I never thought of a LED strip dimmer…! Thanks for the information. 

I think your set up is going to work well. Having the 6a output on your power supply should be more than enough to amperage to power almost any circuit. You’ll just have to watch out for your circuit’s overall resistance though, as the 12v might not be enough pressure gradient to push current though high resistance circuits. But as always, give it a crack and see if it works!

I read your email with great interest - thanks for sending it.
I received the Kanthal wire yesterday. I got the 0.32mm 28 AWG Kanthal A1 gauge wire.
From this website:
It states that Kanthal A1 for 28 AWG is 0.439 ohms per inch. Now, if I construct a HWFC with about a 24 inch length of wire this should give a resistance of 10.536 ohms (24in x 0.439 ohms). Which if I use a 12v supply the wire should draw (presumably) a maximum of 1.14 Amps (12v ÷ 10.536 ohms) and also presumably the wire should be glowing. Please let me know if my calculations are incorrect or I've overlooked somthing. :)

I am still waiting for the dimmer switch and adaptor, hopefully these should arrive soon then I can start construction.
I'll let you know what happens...... success or failure!! :D

All your calculations look correct to me, I’m just not sure about the amperage-to-heat ratio. In the world of NiChrome 1.14 amps really isn’t that much at all. But, if a low amperage like 1.14 can heat up Kanthal enough to glow… it will be a great low amperage alternative to NiChrome. Now you’ve peaked my interest, lol, let me know how it goes.