PC Mods Bay Bus

SUMMARY: An versatile, well built, variable voltage controller for fans or other 12 volt devices.

The good folks at PC Mods sent us a sample of their Bay Bus Kit – Model 1201 – to test out. This is a 12 volt controller you can use for fans or any other 12 volt device (max: 6 watts per switch) that you might want to vary as follows:

• ON at 12 volts – Red Light
• OFF – No Light
• ON at anywhere from about 5.5 to 11 volts – Green Light

The kit comes with a very complete instructions – very easy to follow. All you need to install the Bay Bus is a 1/4″ drill, a small screwdriver and a wire stripper. It’s pretty simple:

• Drill 8 1/4″ holes in a slot cover with the supplied template;
• Strip the wires about 1/4″, stick them in the appropriate hole in the wiring block and tighten the wiring block screws;
• Place the four small LED bezels in the top four holes;
• Carefully push the unit into the 8 holes; you will probably have to bend down the power transistors a little to clear the back of the slot cover;
• Place the retaining nuts on the four switches and tighten;
• Insert the slot cover into the PC;
• Hook up a hard drive power connector.

It took me about 10 minutes to figure out where I wanted the holes to line up and drill them out. The template has a sticky tape on it so it doesn’t move around – only problem I had was it was so sticky I thought the cover would snap while taking the template off after I drilled the holes. However, it lined up perfectly.

Now don’t think this is a 10 minute job, however. If you’re going to use one of these, you have to figure out what you’re going to control and how you want to run the wires. Once you have the wires, you have to place them in the wiring block BEFORE you mount the Bay Bus onto the slot cover; the retaining screws are covered by the slot cover.

Then you have to use the small screwdriver to adjust the yellow trimpot for the low setting – impossible to do once you snap the Bay Bus in place. If you want to change anything once it’s installed, you have to remove the slot cover. I think it’s best to run four wires from the wiring bus and connect up devices to these wires – this way if you just want to add something or change a fan, you don’t have to disassemble the unit.

It might be possible, depending on your case’s dimensions, to use the Bay Bus without removing the metal slot cover. If you do, you must make absolutely sure that nothing contacts the back of the PCB.

I hacked the Bay Bus slightly: As the picture below shows, I cut small piece off the PCB above the wiring block so the wires would not be crimped for space (a good way to void the warranty).

There’s a couple of other things you might consider:

Rather than use a slot cover, you can mount the Bay Bus directly onto the case’s front plastic cover. Every case I have seen has enough clearance to do this, as long as you have a flat place to do it. Of course, taking off the cover requires that you have enough slack so that when you do so, it does not rip the wires out of the unit.

You might want to forget about using the 4 wire connector and solder wires right onto the back of the PCB. If you look at the connector, you can readily see where the power leads are on the back of the board. It’s an easy solder as the pins and the traces are very large – not a delicate job. The advantage is that you can run the wires more easily.

I ran the Bay Bus with some 120mm fans to see how warm the power transistors would get – slightly warm to the touch, not the least bit hot.

The only reservation I have about the Bay Bus is the long term use of a slot cover as a switch plate; a lot of slot covers I have seen are not all that secure and a “wiggly” slot cover may not be the best mounting plate. I would opt for mounting it on the front of the case, if you can.

In summary, this is a well made, versatile device controller that can be used per your imagination. Multiple devices can be used on each switch as long as they don’t exceed 6 watts total, so conceivably you could control something like 12 80mm fans. Why you have 12 80 mm fans is another issue.

For folks who leave their PCs on 24/7, I could see this product as one way to control noise; go into “high gear” when you’re playing Quake, power down at idle times. Could be a real sleep saver.

I want to thank PC Mods again for allowing us to evaluate this unit.

Email Joe