A recent thread on soldering irons reminded me of an idea a had for some time...
Do you think it is possible to measure the temperature of the soldering iron by measuring the resistance of the heating wire (probably NiChrome)? I checked -- Nichrome wire has a tempco of about 0.04% / degree C.
I visualize measuring the current or resistance during one half of the ac power line cycle to get the temperature. I would control the power during the other half of the cycle using an SCR to set the temperature.
Do you think it is possible to measure the temperature of the soldering iron by measuring the resistance of the heating wire (probably NiChrome)? I checked -- Nichrome wire has a tempco of about 0.04% / degree C.
I visualize measuring the current or resistance during one half of the ac power line cycle to get the temperature. I would control the power during the other half of the cycle using an SCR to set the temperature.