Oh the smell at trade school, when we first made acquaintance with electrolytics and our bench power supplies. Each workspace had low voltage AC and DC sockets built in and it was great fun to "mine" the bench of someone else while he was away, then when he came back surreptitiously turn on the power, which was some distance away for each row of benches. They made us solder this, btw, the Testofon tester :   It's a simple but surprisingly versatile tester. The video is in German but you'll get the gist if you click around a little in the time line. https://youtu.be/D31ItpvJ3TY This is the current kit for education and schools to learn basic soldering: