Can series diodes in an electric soldering iron achieve cooling?
The DC power supply directly supplies power to the soldering iron. Since there is no temperature detection and control circuit, the temperature cannot be kept constant and will vary with the soldering area. If the temperature is too low, the speed of tin melting may be slow, and if the temperature is too high, the tip of the soldering iron may be oxidized too quickly, resulting in no tinning. To solve the problem of constant temperature, the ideal way is to increase the temperature detection and control circuit. If the ordinary electric soldering iron used is modified, since the soldering iron itself does not have a temperature detection element, it cannot be changed to temperature control, and the temperature can only be lowered by reducing the voltage.
Ordinary diodes, depending on the model, the forward voltage drop of ordinary rectifier diodes is generally around 0.7V, and the forward voltage drop of Schottky diodes is even lower. If the soldering iron is powered by power frequency alternating current, the diode in series can play a role in reducing voltage, because the effective value of the voltage will be halved after the alternating current is rectified by the half-wave of the diode. But for the DC voltage, the ideal voltage drop of the diode is only 0.7V at most, and the range of the voltage drop is too small, which has no obvious effect on the temperature drop.
If you want to reduce the temperature significantly, you can only reduce the voltage significantly. There are two ways to reduce the voltage. One is to change the reference voltage of the voltage sampling part of the internal output of the charger. This change method requires certain circuit experience and foundation. Another method is to use a finished DC adjustable step-down module to change the output voltage through a variable resistor. And it can be modified to automatically cool down, and the detection element can be added to the soldering iron stand, and the voltage will be automatically lowered after the soldering iron is put in.
