First noob post. Did a search, saw things for 10+ LEDs. Quick question for anyone that would know. Think I would be able to hook up 4 x 3mm red LEDs in parallel with nothing else to my motherboard for hard drive activity with out blowing the board? Thanks.
I wouldn't recommend it. Grab an optocoupler and a couple of resistors while you're buying the LEDs instead. Unless anyone actually knows how much current a motherboard can source (I don't off the top of my head )... Still, it's not like 3 red LEDs will be a huge load...
Other idea was to find out if ground of the pins does the flicker. Then I should be able to run the 4 LEDs in series off 12V+ grounded to the motherboards HD light negative?
Use an optocoupler or place a base of a transistor on the output from the motherboard pin. Connect the +12v input to the collector and put the LED's between the emitter. Then connect both grounds.
(Gotta understand that this is my first time in years that I've made a board) So..... 1. Positive HD light from mobo to anode on optocoupler. 2. Negative from HD light mobo or ground from psu(??) to cathode on optocoupler. 3. 12V+ from PSU to collector on optocoupler. 4. Emitter on optocoupler to 220 ohm resistor to 4 LEDs in series to ground? What optocoupler would I want to use for this?
Yeah that would do it, use a 4n26 they're fairly popular. Though a single trasistor will work just as well. Yeah you wont have the electrical isolation but its such a low power circuit I dont think you need to bother about it
Would a 4N35 work too? Only reason I ask is a local store has 200+ of them, but nothing else in stock. Appears they're pretty much the same? Edit: NM, I see the differences now.
