This is the heating element I ordered off eBay. After examination I found out that it is not any different from my previous attempt to heat the bed. It is comprised from nichrome wire wound around a cardboard, I can not identify what it is made of, sandwiched between an aluminum heatsink and an aluminum plate. After screwing it on the bed, it achieved the required temperature after about 5 minutes. The only downside I see for the moment is that the heatsink is very tall and there some leakage which is about 40V. Touching it while connected on the grid, it didn't kill me so I suppose it is "safe".
After leaving it on for 2 hours, no smoke appeared, so it seems to be working good. Soon a temperature sensor will be added.
