LED Tester

Check and compare intensity

LEDs are used everywhere these days, not just as on/off indicators any more but now also as a source of light. Before you mount an LED in your circuit it would be nice if you could first check whether you have the right type and how much current it needs to have for it to be bright enough.
The simple circuit described here allows you to test LEDs quickly and make a distinction between low-current and high-efficiency types.