Power control is useful when soldering. It allows to keep the temperature of a soldering tip at the optimal level, reducing its destruction and extends its life. I found in the Web two circuits of microcontroller power regulator by L.I. Ridiko. These devices are control the power by changing the number of half cycles through mains soldering iron on the second. The higher power set, the more half-cycles will go on a soldering iron and the less will be a pause between them. the device uses an algorithm Bresenham for pulse shaping. The device uses an Bresenham's line algorithm for pulses generation. Because the switching occurs in moments of transition of line voltage through the zero, electrical noise, caused by the regulator, will be minimal.
I used the first circuit as basis. I ignore the galvanic isolation and replaced optical thyristors to the general thyristor and the diode rectifier. The result was such an electronic circuit:
The device is assembled on two PCBs:
Control the device is performed by two buttons. One increases the power, the other decreases it. Simultaneously pressing both buttons resets the output to zero or set it to maximem (99) if it was already zero.
Electronic circuits, PCB layout and firmware can be downloaded from the links below.