I have a Darlington transistor to keep cool. It is a lovely chunky TIP147 in a TO247 package, attached to a PC heatsink (£6 from ebay) to get the heat out. PC heatsinks are great as they often include ...

This circuit idea is certainly not new, but when it comes to making a trade-of between using a small, short-circuit proof transformer or a capacitive voltage divider (directly from 230 V mains voltage ...