I have a little heating pad 12" X 15" runs on AC 120 volt has around 220 ohms resistance on low final got to hot burned up wire. What to replace it with using junk box parts light bulb wastes 10% for light would need metal cage to keep bulb from breaking seems like not good way. Have 300 feet coated 40 gauge copper wire only problem would be keeping that much wire all separated so does not short out almost impossible. Then I come up with what I think should work change 120 Volt AC to 12 Volt AC or similar voltage that transformer may put out. If you use 12 Volts AC and 27 gauge wire 60' feet this would be easier to manage. Just take the volts the transformer puts out X volts / divided by watts this will give you resistance then find copper wire with that much resistance and it should work will it not? I am think'n old printer cables or monitor cables have fine stranded wire which would stand up good under bending conditions.