Well it was bound to happen sooner or later. I fried an LED.
Maplin is open on Sundays, so I popped over to get some of those components to make a 5 volt power supply.
It worked. I put a red LED on the +5v coming from the circuit and connected the other end to ground. It lit up, for a while. I noticed this smell of hot electronics then the LED faded away. The bulb was hot, the voltage regulator (78L05) was hot. Not good!
So I rememeber reading somewhere, always use a resistor with an LED. So I put a 1K resistor in front and then found another LED and it was fine. Not hot anywhere.
Here is a diagram I made using CircuitMaker Student Edition which was free to download: