Okay... I basically need to somehow do something like bit-tech's HDD power LED project.. (ref http://www.bit-tech.net/article/58/ ) BUT i want the basic power LEDs to be on all the time and not alternated when there is HDD activity... DOes anybody know any good ideas how to mod the circuit to allow this? Partly because i'm connecting the outputs to my Volcano9 CoolMOD.. And also to LED strips later on. The COolmod looks much better with the base blue LEDs constantly on so i dont' think i would like the thing to be alternated. Help!
okay...forget the main power lEDs...i was so silly to forget i can hardwire it. Thanx for the drawing anyways I knew THAT Now i need to know HOW i can setup a LED strip to take a 3v Motherboard HDD indicator light...add in an optoisolator, and a LED buffer with an external 12v source to DRIVE the LED strip BASED on the 3v's HDD indicator...now that's my question. Thanks
I didnt use an OptoIsolator, but here you go: www.zapwizard.com/IDE You should be able to mod this to run as many LED's as you wish if you use an Opto and Transitor. A few more circuits at www.zapwizard.com
you could slap an opto-isolator to replace the switch on my diagram then wire that to your MoBos HHD LED output
Thanks, zapwizard and acrimonious... One more question. (I'm familiar with electronics, just not too much on the 4nxx series of opto-stuff) the 4nxx series basically takes the 3v, lights a LED inside to create a relay-ish output on the other 2 pins? so basically ----- 12v ----- OPTO -----Rest of LED network | | ------ 0v ------ | | | ------ 3v fr HDD LED so OPTO acts as a "relay" for switching the rest of the LED network based on VOLTAGE input. is there a resistance level?
Yes, it acts as a relay No, the opto's phototransistor does not have any resistance built in. The opto can't handle the current from all those LED's. So to run the amount of LED you want you will need an extra npn transistor, AFTER the opto to handle the additional current. (Use CODE tag to use spaces) Code: +12volts-----+------------------------C +---Opto------B Transistor E-----LEDs----Ground
So this is what i'll be building. Please comment.. Code: +++12v++++|PIN5-BASE|+++++| +++HDD LED 3v+++|PIN1|+++OPTO++PIN5-BASE+12V++LED NETWORK -----HDD LED 0v------|PIN2|+++OPTO---PIN4-Emitter-0v---LED NETWORK PLease help me out..bit unsure. ON the LED network will be 350ohm resistors PER LED. Between 12v and PIN5 BASE will be a 10k resistor for reasons i just copied it from the bit-tech article. comment...please. Please advise.
I would go a little bit different direction, but the fundamentals are the same. Hopefully you can live with 9 LEDs instead of 10. The 4N27 optoisolator is good for 150 mA of collector current. That's the target you need to keep in mind. So 10 parallel 20 mA LEDs, that's over the rating. But since we can use 12V supply on the transistor side, we can combine up to three blue LEDs (or five red ones) in series before the cumulative forward voltage exceeds the supply. So the load to the opto should look like three prallel legs, each of which contains three LEDs and a resistor. Total collector current will be 60 mA, which is well inside the spec. In fact you could double it. Code: +--/\/\/--|>|--|>|--|>|--+ | | emitter o--+--/\/\/--|>|--|>|--|>|--+--o gnd | | +--/\/\/--|>|--|>|--|>|--+
Why not this? 12v-------------==------------------------------------------------------------------- + [COLOR=royal blue]***********[/COLOR]Resistor[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]| [COLOR=royal blue]*************************[/COLOR]LED[COLOR=royal blue]*******[/COLOR]LED[COLOR=royal blue]*******[/COLOR]LED[COLOR=royal blue]*******[/COLOR]LED[COLOR=royal blue]*******[/COLOR]LED [COLOR=royal blue]**************************[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]|[COLOR=royal blue]*********[/COLOR]| Ground-------------------------------------------------------------------------------- - It's just a parallel circuit. If you're using 2 or 3.5V LEDs then you could run them off the 5V line of your PSU and use a 1/4 or 1/2W resistor. Oh, wait, I don't even know if what I said is useful anymore...
