The Velleman PS3005D programmable dc lab power supply is, in my opinion, a overall good value item, but there are room for improvement. One of those improvements is most definitely the cooling fan! The stock fan does the job, and is also moving a pretty good amount of air, but it is quite noisy. So here I am going to show how I replaced mine with a high quality fan from Noctua.
The new fan
The new fan is a Noctua NF-R8 Redux 1800, which is a 80x80x25mm fan.
Important! The fan can’t be more than 25mm deep, or it won’t fit in! You also wouldn’t want a super low noise fan, since they tend to also move a lot less air, which could end up being a big problem.
Anyone who had a Noctua fan will notice it isn’t in the normal Noctua colors, which are very………. ‘different’ from other fans.
The first thing we need to do can’t come as a surprise, we need to get the cover off!
To get the cover off, simply take out the screws on each side and lift it up while tilting it a bit forwards.
Inside we find a few boards and a big transformer at the bottom, but to replace the fan we only have to take the board at the back out.
Notice, some of the connectors got hot-glue on them, carefully cut that off so you can get the connector off without pulling too much on it. The connectors without glue got a little lock, simply press the end closest to the wires while gently pulling to get those off.
Before we can take the board out, we need to cut the wire for the fan.
Before cutting it, gently pull on it until it won’t go any longer.
I decided to cut it here, just so I can use the fan for something else if I want that at some point. After cutting the wire you can take out the four screws on the back, and the whole assembly with fan and board will come out as one unit.
With the board out, next step is to take the fan off.
But first… Let’s see what this is! Hmm, good quality dc fan? Whatever… At least it was a decent place to save some money to keep the cost down.
To get the fan separated from the heatsink, simply loosen the nuts in each corner. And don’t lose the shakeproof washers!
If we take a look at the heatsink, it is actually a pretty clever design.
The heatsink is one big piece of aluminium, with some taps bend down. Those taps are directly in the path of the airflow and it seems to work pretty well too.
When putting the fan back on, pay attention to how it is rotated compared to the board. Putting it on like this makes the wires come out of the fan right next to where the wire in the power supply is located.
Put the shakeproof washers on and the nuts afterwards and tighten, but not over tighten them.
Put the assembly back in, and mount the fan with the screws that either came with the fan, or use the ones that held the original fan in.
Here you can also see why the fan can’t be any deeper than 25mm. There are only around 1mm between the capacitor and transformer.
The last thing we need, after connecting all the connectors again, is to connect the new fan to the wires the old was connected to.
Remote a bit of the insulation on both wires from the fan and power supply, and pre-tin them.
Put some heat shrink tubing over the wires and solder them together.
Finish off by shrinking the heat shrink tubing, and wonder what that yellow wires is, and why it is there.
The yellow wire is from the fan, and can be used to calculate how many rpm’s it is spinning at. I don’t need that yet, but just in case I get bored and suddenly decide I want to know how fast the fan is spinning, I am leaving it.
At the front of the power supply, you can pull a bit on the wire for the fan so it gets out of the way and hides under the metal rail.
I ended up with the yellow wire following the other wires to the front of the power supply too.
And that’s it! All you need to do now is to put the cover back on, and enjoy a nice and silent power supply!