This is a simple flashing led circuit with 2 leds and 2 NPN transistors. It illustrates the behavior of transistors and capacitors and if you use an oscilloscope it will be very easy to determine what ...

This is probably the simplest idea to generate flashing light from an LED using AC. The circuit is relatively the simple way of flashing one or more LEDs from a high voltage DC obtained from Mains.

LED flasher circuit With cycling safety in mind, I bought a pair of low power red LED things that replace the bungs in the end of drop handlebars. They are a neat way to get a bit of extra visibility ...

In Figure 1, National Semiconductor's LM3710, a supervisory circuit, is configured to reduce the power consumption of a traditional LED indicator by 99%.

They look for all the world like any other LED, though embedded in the plastic dome is an integrated circuit to do all that flashing work.