Take a look at the 555 timer IC. The datasheet should contain what you need. Also search Google for "LED flasher". You can blink any bulb by adding the appropriate driver transistor.
Assuming you will want to flash something larger then an LED, you will need a transistor to switch it on and off. The 555 cannot sink enough current. So roughly, you would connect the base of the transistor to the 555 via a pullup resistor, your emittor to ground and then the collector to the device you are flashing (with the other side of that device connected to 12V).
I'm a fan of doing really basic stuff in software. It's infinitely modifiable. Go for a $2 Atmel or PIC micro, use it to run one of the high power enhancement mode FETs - a 12A, 60V FET costs AUS$8 so it has to be half that there. Throw in a 7805 regulator and you should have the circuit done in an afternoon, the software will take you 5 minutes and all for under $10. I'm pretty sure the PICAXE chips don't need programming hardware but you'd have to check.
Hi, If you need a flasher circuit then you could use two transistors connected to give astable pulses, that way you can oporate the flasher with 12v and will keep the LED driver there.
Edited by - TechnoFreak on May 25 2006 11:23:26 PM
another Flashing question
Posted - May 05 2006 : 08:57:04 AM
