Computer Forums - View Single Post - What cicuitry do I need to make two clusters of led's flash alternatingly.

horndude · 09-02-2007, 04:34 PM

led's use 1.2 or 1.5 volts I believe, about 20 milliamps of current each

use a separate transistor to drive each cluster, each needing 400 milliamps or about 6 watts

transistors themselves, nothing special, any small signal npn or pnp transistors will work for the oscillator part, 3904's would be fine, to drive the led's something a bit beefier will be needed, 1/4 watt or 1/2 watt resistors, small capacitors, nothing special here

but don't know what values needed unless LED specs are known and the desired flash or cycle rate

any more explanation than this and you will be over your head, seriously, unless youve got electronics experience and you dont, even something as simple as this

google for electronics kits and get an LED flasher kit then use its output, much easier this way

wanna do it the hard way and solder on a perf board then head to radio shack and spend like $5 for the parts plus tools if you dont have a soldering iron and stuff

Im not gonna design or build this for you, the wikipedia link already has the schematic, those values will give you a 1/2 second cycle rate

09-02-2007, 04:34 PM	#6 (permalink)
horndude Master Techie Join Date: Apr 2004 Posts: 2,534	Re: What cicuitry do I need to make two clusters of led's flash alternatingly. led's use 1.2 or 1.5 volts I believe, about 20 milliamps of current each use a separate transistor to drive each cluster, each needing 400 milliamps or about 6 watts transistors themselves, nothing special, any small signal npn or pnp transistors will work for the oscillator part, 3904's would be fine, to drive the led's something a bit beefier will be needed, 1/4 watt or 1/2 watt resistors, small capacitors, nothing special here but don't know what values needed unless LED specs are known and the desired flash or cycle rate any more explanation than this and you will be over your head, seriously, unless youve got electronics experience and you dont, even something as simple as this google for electronics kits and get an LED flasher kit then use its output, much easier this way wanna do it the hard way and solder on a perf board then head to radio shack and spend like $5 for the parts plus tools if you dont have a soldering iron and stuff Im not gonna design or build this for you, the wikipedia link already has the schematic, those values will give you a 1/2 second cycle rate