43 Led alternate flashing strobe circuit

This circuit is based around the 555 timer chip operating in astable mode. The rate of flashing is set by the 2 resistors and capacitor to the left of the timer chip. The output of the chip is connected to 2 sets of Leds via transistors. The top set uses a pnp transistor and the bottom set uses an npn transistor. This would allow for the addition of a lot more leds as the 555 timer chip can only sink and source up to 250 mA max. In this configuration the timer chip is only sinking a few milliamps and so will never get very hot and it's lifetime will be greatly increased. If you have any questions or suggestions for improvement please comment.

published 11 years ago