ORIGINAL: 3d Marky
Amendments to the designs.
1) Why not use a 3.3 ohm ballast 10w resistor instead of a 2 ohm if you struggle to get 12v from your supply. Using 3.3 ohm means you can still use just a single 10w resistor using the case as a heatsink. Wattage will be around 8.75
I found that there is only a minimal increase of .1 - .15 of a volt between the two values.
Once you go below 3.3 ohms you must use two 10w 1ohm resistors in series (2 ohm’s) as the current will be above 13.5w and will burn out a single resistor.
2) Only bundle 2-3 wires of each colour together when soldering to the connectors. You do not need to use all the wires as stated in the tutorials as the current will never be that high. Cut off the unused wires or your end up with a mess in the case.
3) The ATX cooling fan can be very noisy so simply add a 50ohm 1/2w resistor or higher in line to the positive of the fan. This runs much quieter but still gives a reasonable air flow through the case.
1) The 3 local-ish Radioshacks never seem to have anything but the 10 watt, 10 ohm resistors so thats why I went with them. The ones you listed will work if you can find them.
2) My instructions say to solder 3 wires to each plug, and later that you dont have to do 3 wires but should at least 2.
3) Good idea. Some high quality bearing oil (I use Singer bearing oil......yes the sewing machine company) or a ball bearing fan will cut down ont he noise a lot too. If you are going to oil the fan dont use wd-40.