I want to operate a 1-inch length of nichrome 80 wire, 26 gauge, at 200 - 600 °F. This type of wire has 2.657 ohms of per foot. So, for 1", there would be 0.22 ohms in the wire. According to my amperage chart I will need between about 1 amp and 2 amps to operate in my desired temperature range.
The problem is that according to my calculations I would have to run at 0.5 volts if using 2 amps and 0.25 volts if using 1 amp. This seems like a very small voltage to me.
For example, my power supply, a standard benchtop supply has 0-3 amps and 0-50 volts. The voltage meter on my power supply has gradations in 2 volts. In other words between 0 and 10 there are 5 tick marks. So, to run at 0.25 volts, for example, I would have to have the gauge at 1/8th of tick mark -- a tiny amount on the gauge. It seems like if I just nudged the voltage knob a tad too much I could blow out the wire.
I am doing something wrong here? Do I need some kind of special, ultra-low voltage power supply, or are my calculations wrong in some way?
What if I put a resistor in series with the wire? That would increase the voltage needed, but I would still need to operate at a very exact voltage, right? For example, if I added a 5 ohm resistor, then operating at 1 amp would seem to require 5 volts, a more normal voltage, but once again am I risking a burnout if I nudge the know slightly too far?