Here is a simple but inexpensive inverter for using a small soldering iron (25W, 35W, etc) In the absence of mains supply. It uses eight transistors and a few resistors and capacitors. Transistors Q1 ...

Soldering to a PC board can be tricky: Too much heat can make the copper trace lift right off the board substrate. Use a soldering pencil rated at 15-25 watts, no more. (Watch the video; story ...

This is the most complex or detailed soldering I've done so far, the QFN20 package is very small but still not impossible to solder using conventional tools. In this video I make a functional circuit ...