I have a soldering station equipped with a 24V/60W soldering iron. Its heating element (pins 1-2) resistance measures around 50 ohms. The resistance of the thermocouple (pins 4-5) measures around 2 ohms.
Soldering Iron Pinout
PIN WIRE PURPOSE 1 Blue Heating element ' ~50 ohms 2 Green Heating element ' 3 Yellow Case ground 4 Red Thermocouple ' ~2 ohms 5 Black Thermocouple '
I also have a desoldering gun from a desoldering station with the same power requirements and ratings 24V/80W. The thermocouple resistance measures the same as my soldering iron around ~2 ohms (pins 1-2). The resistance of the heating element (pins 3-4), however, measures only 4 ohms.
Desoldering Gun Pinout
PIN WIRE PURPOSE 1 Black Thermocouple ' ~2 ohms 2 Blue Thermocouple ' 3 Red Heater Element ' ~2 ohms 4 Red Heater Element ' 5 White Trigger switch 6 White Trigger switch 7 CENTER Vibration sensor
Both instruments are using a ceramic heater. The temperature range for the desoldering iron is 160℃ - 480℃ I don't understand how the heating element's resistance can be so low. Am I missing something here? If I were to connect the heater and thermocouple wires of the gun to my soldering station, wouldn't it overheat? If so, why doesn't it overheat when connected to the desoldering station given the units have very similar power requirements. Is there some other internal circuitry I am not accounting for? Am I misreading something?