I know that there are better and more reliable ways to generate heat. I did this experiment mostly for fun.

I got the idea to draw a serpentine pattern on the unused area of a PCB, and to test how much heat I could produce with it before melting the tracks. On the left, you can see what it looks like. It has a 3.6 ohms resistance. I think this PCB could be used for "useful" applications.

I first tried to heat the PCB using my bench power supply, which is able to regulate current. It has not been too long until I reached the maximum current the power supply could provide. 3 Amps were flowing through the PCB, and it was quite hot.

Next, I decided to try something else: Boil Water with the pcb. I filled a container with water, and inserted the PCB in the water(see picture):



Of course, it was necessary to use a more powerful source of current than the previous one. I used my 10 Amp Variac, connected to the mains. I installed my ampmeter in the circuit, and raised the voltage progressively.

Warming up...

At first, I was very careful not to raise the power too quickly, in fear of melting the PCB tracks. On the picture on the left, there had been 5 Amps flowing in the circuit for several minutes. The water was getting hot, but not boiling.



Finally, I raised the current up to 8 Amps. A few moments later, the water was boiling. I could hear a 60hz hum coming from the variac too...