Analysis of the cooling effect of electric soldering iron series connected with diodes
The purpose of serializing diodes is to reduce voltage and solve the problem of high soldering iron temperature. Below is an analysis of whether serializing diodes can achieve the goal of cooling down.
The DC power supply directly supplies power to the soldering iron, but without the addition of temperature detection and control circuits, the temperature cannot be kept constant and will vary with the welding area. If the temperature is too low, it may cause slow tin melting speed, while if the temperature is too high, it may cause the soldering iron head to oxidize too quickly and prevent tin from being applied. The ideal way to solve the problem of constant temperature is to add temperature detection and control circuits. If a regular electric soldering iron is used for modification, as the soldering iron itself does not have a temperature detection component, it cannot be changed to temperature control and can only be cooled by reducing pressure.
For ordinary diodes, depending on the model, the forward voltage drop of ordinary rectifier diodes is generally around 0.7V, while the forward voltage drop of Schottky diodes is even lower. If the soldering iron is powered by power frequency AC power, the series diode can have a voltage reduction effect, because the AC power is rectified by the diode half wave, and the effective voltage value is reduced by half. However, for DC voltage, the ideal voltage drop of the diode is only 0.7V, and the amplitude of voltage reduction is too small, which has no significant effect on temperature reduction.
To significantly reduce the temperature, the only way is by significantly reducing the voltage. There are two ways to reduce voltage. One is to change the reference voltage of the sampling part of the internal output terminal voltage of the charger, which requires some circuit experience and foundation. Another method is to use a finished DC adjustable step-down module, which changes the output voltage through a variable resistor. And it can be modified to automatically cool down, and detection components can be added to the soldering iron frame. After the soldering iron is placed, the voltage can be automatically lowered.
So, using a series diode to cool down is not ideal for the final effect due to the small amplitude of the reduced voltage.
