arhi added PID control to the DIY soldering station. This graph shows that the temperature stays solid even on a wet sponge and in a glass of water:
As you can see 280sec into the test I pushed the soldering iron on the dump sponge and held it there until 320sec then I let it “rest” up a bit and then I pushed the tip into the glass of water for 20-30sec .. As you can see the output pwm gave it bit more juice and the temperature didn’t miss targeted 250C by nothing serious. PWM output is only 0-15 levels so not a very high resolution but seems more then capable to keep this baby spot on (0.1C is the play during stable time, when you solder it moves ~0.3C +- that’s not noticeable on this graph, and strong cooling like sponge/water get it to skip 5-6C but nothing significant). The data on graph is sampled in every ~100-110ms while PID routine is called only once per second.
Via the forum.