RED FLASHER LED, T-1 3/4

When a Flashing LED is fed from 12 vdc through a current limiting resistor, MEL is quite right when he states: "when the LED turns off, the entire suppy will be applied to the internal chip." A series zener diode is not the best solution, however, because any change in supply voltage will be seen in nearly it's entirety across the flasher. A better solution is
to feed the flasher through a current limiting resistor and to place the zener diode across the flasher to limit chip voltage when the LED turns off. The zener diode can also be used as shunt voltage regulator to minimize LED brightness change as a result of supply voltage changes.

Operation from a 12.5 vdc supply through a 330 ohm current limiting resistor resulted in an "on" voltage of 4.9 volts. A 7.6 volt drop across a 330 ohm resistor calculates out to an LED "on" current of 23 milliamperes.

I have used these as flashing lights on R/C planes. Low weight since you dont need an external board to make them flash.

Great LED use them to retrofit old Halloween decorations so batteries would last longer using leds instead of incandescent lamps GREAT PRODUCT REAL BRIGHT

Look under the designation BH-321 (a 2-AA 3V snap holder); You can make a flasher that might appear to be an intrusion alarm to a would-be burgular. You need this part plus the BH-321, as well as a 9V snap, which you might get free if you cut off the top 3mm of a dead 9V battery. The cost is only $1.20, excluding the 2 AA's and the snap. BH-321 has simple instructions.