I'm trying to make a fanbus for 4 LED fans i put some bi-color LEDs in, and 2 with normal LEDs. bassically i want 2 swtiches, 1 switch to control the fan speed, either 5 or 12 v. and the second switch to select a led color on the bi-colors. so im looking to make a pcb with a floppy connector, 4 3pin connectors (2 for switches 2 for the single color fans) and 4 4pin connectors for the bi-color fans. I know enough to design the fan speed control half but i dont know about the LED part. the LEDs are yellow and red, 1.8v-2.2v blue 2.8-3.2 max forward current 30ma for all the bi color is red/blue if i were to wire all the connectors in parallel, and all the leds on the fan in parallel, then get a vreg for each color would that work? and if so what would the specs for the vreg be? i drew a pcb layout of this and if that will work can someone please give me what specs i am looking for in the vregs?
eh? yo need to explain that ALOT better. i have read it three times n still cant figure it out. is that 6 fans, 4 with 2 lots of leds for 2 colours and 2 fans with just one colour. where does the vreg come into it? BTW that PCB can be made alot more compact... try n fill as much space as u can with copper, wastes less etchant.
allright ill try again. the "ghost fans" (the 4 4-pin connectors on the bottom) will have 4 bi-color LEDs in them (3 pin common cathode kind, red/blue with 2.2v and 3.2v max respectily) there will be up to 4 of these. the "Pac Fans" (2 vertical 3pin connectors in the middle) will have 4 yellow LEDs (2.2v max) there will be up to 2 of these. the 2 horizontal 3 pin connectors are for spdt center off switches. one to control 12v or 5v (fans) and one to control which color LED (red/blue)will be on (the yellow ones on the pac fans will be on either way.) the 4 pin connector at top will be a floppy power connector. my question is: how do i power the LEDs? I want to be able to disconnect fans and not have it affect the ones still plugged in. vregs were mentioned because one of my freinds said something about them. they would be the other 3pin components. diodes so the yellow is on whenever the switch is on either on position (did i put those facing the right direction?)
why the diodes for the yellows, just bypass the switch for them (unless u want center off for them which is what i guess you want (dont forget to allow for a 0.8v drop over them).. you will need a resistor PER led string, your best bet is to solder them into the loom that will be plugging into the board, or obvisally modify the board to allow them, but if you leave the board switching 12v to the led header then you can modify it later (led wise) and not have to unsolder any resistors. only prob i see is the FANS header (top right) switches the live to the fans between 5v and 12v, resuling in either 5v (maby not even running) to full 12v, shouldent u switch the GND between 5v adn ground to give 7-12v swing (p.d) still dont really get the right hand side of the circuit, seems a bit weird....
It would help if you showed the circuit diagram as well as the pcb layout. Voltage regulators can either give a fixed voltage output or a variable one, but if you only want 5V/12V there's no point in using them, the PC PSU has those voltages on each molex.
I do want the yellows center off which is why those are there. thanks for the .8v drop, i didnt know about that. i redid the board for a resistor between the output of the leds switch and each connector, 1 per output per connector. i dont plan to be changing the leds and i kinda want a board that has a few componants on it because it will be in view of the window so it should look cool. with the fans header, i would do the 7-12 swing one but then i would need a separate ground for the leds and the fan and i believe these fans will run at 5v. ($.99 each! for clear 4 led cooler master fans.)
