Badders
Newbie level 1
Hello, I was hoping to make something similar to this for my girlfriends birthday.
The wire tip at the end of the torch is ~ 1.5" of 26awg nichrome wire. at 2.5 ohms/foot I make that to be about 0.31 Ohms. The colour is cherry red indicating about 900'c.
I found a table on wiki;
http://en.wikipedia.org/wiki/Nichrome
Current (A) vs. temperature characteristics, straight wire.
This states that to get a piece of 26awg nichrome to 900'c it requires ~ 6.5A.
So I need a DC power supply capable of 6.5A through a load of 0.31ohms. so Vout would be 6.5x0.31 = 2V, however it might be nice to have some head room in the circuit so I can use a larger tip. 23awg would probably be ample so;
23awg @ 1.3 ohms/foot. 0.16ohms per 1.5" (length of wire tip)
24awg @900'C needs 9A. 9A x 0.16 = 1.4V.
My plan was to use a 12v dc power supply to drive a DC to DC converter.
DC;DC converter something like this I thought would be suitable. **broken link removed**
The info of the datsheet that interested me was;
Iout= 10A
Vout is adjustable from 1.2V to 5.5V
short circuit protection is auto reset @ 20A.
So I figured if I hooked up a pot to adjust the output voltage this would adjust the output current and hence control the temperature of the wire tip.
Any advice would be greatly appreciated. Im doing this to try and save some money and learn a few bits.
thanks, Will.
The wire tip at the end of the torch is ~ 1.5" of 26awg nichrome wire. at 2.5 ohms/foot I make that to be about 0.31 Ohms. The colour is cherry red indicating about 900'c.
I found a table on wiki;
http://en.wikipedia.org/wiki/Nichrome
Current (A) vs. temperature characteristics, straight wire.
This states that to get a piece of 26awg nichrome to 900'c it requires ~ 6.5A.
So I need a DC power supply capable of 6.5A through a load of 0.31ohms. so Vout would be 6.5x0.31 = 2V, however it might be nice to have some head room in the circuit so I can use a larger tip. 23awg would probably be ample so;
23awg @ 1.3 ohms/foot. 0.16ohms per 1.5" (length of wire tip)
24awg @900'C needs 9A. 9A x 0.16 = 1.4V.
My plan was to use a 12v dc power supply to drive a DC to DC converter.
DC;DC converter something like this I thought would be suitable. **broken link removed**
The info of the datsheet that interested me was;
Iout= 10A
Vout is adjustable from 1.2V to 5.5V
short circuit protection is auto reset @ 20A.
So I figured if I hooked up a pot to adjust the output voltage this would adjust the output current and hence control the temperature of the wire tip.
Any advice would be greatly appreciated. Im doing this to try and save some money and learn a few bits.
thanks, Will.
