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# Need help with conceptual diy heating element for miln

## Need help with conceptual diy heating element for miln

#1
10-08-14, 09:37 PM
Member
Join Date: Oct 2014
Location: us
Posts: 1
Need help with conceptual diy heating element for miln

I plan on building an all purpose kiln for glass blowing but I'm struggling with finding an adequate power supply. I'm checking this one outhttp://www.amazon.com/30-Amp-Variac-Variable-Transformer/dp/B00CLUW6IQ/ref=sr_1_16?ie=UTF8&qid=1412828032&sr=8-16&keywords=30+amp+110+volt+transformer

Now constructing the heating element is fairly simple. A heating element is a length of wire with a high resistance therefore it heats up. You need to use ohms law to determine the type of power supply you need. I think I'm confused though. So you take the resistance of the wire per foot which in my case is 1.6ohms per foot and the table states that for the element to heat up to 2000 degrees needs 5 amps. So do you just do 1.6 ohms x 16 feet x 5 amps. In this case it equals 128. So 128 volts? Then I had I different thought which may be completely the wrong way of thinking. Amperage depends on the size of the circuit so does that mean no matter the length it will only draw as much amperage as the length of wire is able to? Because in this case amperage is dependent on resistance and length of wire.So if I were to use much larger wire I could use a much higher amperage power converter. I'm just looking for some help in this area. There is not very much on the subject on the net I could use the advice. I'm a little lost. Thanks in advance ��

#2
10-09-14, 05:52 AM
Member
Join Date: Mar 2010
Location: USA
Posts: 4,529
As the heating element (nichrome wire or whatever) heats up, its resistance increases. So your calculation of 1.6 ohms per foot can't be simply used in to come up with the wire length or amperes needed.

Thus building your own kiln or oven is not an easy project.

Unfortunately I don't know how to go about computing the length of the wire needed and the amps it is going to draw.

Last edited by AllanJ; 10-09-14 at 06:13 AM.
#3
10-09-14, 06:13 AM
Member
Join Date: Feb 2006
Location: USA
Posts: 6,396
Resistance

Perhaps this will help:

Temperature Coefficient of Resistance