PC fan with external power supply and variable speed - Page 1
Forum section: electronics / beginners

author: BavaroneMUC
author_rank: Newbie
timestamp: September 15, 2023, 09:25:34 am
content: Hey guys,here's the DIY project I have in mind:I'd like to take a 12 V PC case fan, run it off an external power supply, and control its speed in a continuously variable/stepless way.Everything will be mounted inside a wooden case I'll build, which will be as small as possible but as large as necessary.I'd like this not to cost much, and limit the amount of new skills I'd need to learn as much as possible.Its function is to blow the fragrance of a scented cloth into the living room.I don't yet know how fast or slow I need it to run, but I want it to be as quiet as possible.I might have the fan barely spinning - that's why I need the controller to allow me to turn it almost all the way down.I have an extra Arctic F12 PWM fan, which I'd like to use.I've found a PWM controller and simple power supply on ebay.The controller comes in two variants for power:A) with a 3-Pin connectorB) with red and black leadsMy question:How do I connect the controller to the power supply? The power supply I found on ebay has a run-of-the-mill 5.5 x 2.5 mm connector.I guess the best way would be to get the version with red and black leads, buy a socket that fits the power supply, and solder the leads to the socket.I've never done any soldering. It would be a cool project to buy a soldering kit and learn how to do it, but if there's a "plug-and-play" way to connect the controller's male 3-Pin connector to the power supply's 5.5 x 2.5 mm male connector, I'd prefer that.I've done some googling, haven't found a suitable adapter or solution, yet. Maybe I'm not using the right search terms.I've attached a sketch of my idea to this post, which shows the component's I've found, but I'm open to any suggestions or input.In any case, hope things are good in your neck of the woods.All the best and thanks in advance for your input!

author: wraper
author_rank: Unknown
timestamp: September 15, 2023, 09:28:25 am
content: Red to +, Black to -, leave yellow wire unconnected.

author: BavaroneMUC
author_rank: Newbie
timestamp: September 15, 2023, 10:29:25 am
content: Thanks for your input.Maybe I wasn't clear enough.I wasn't asking about how to make the connection by soldering it.I was asking whether there's a connector/adapter that lets me connect the 3-Pin version of the controller to the power supply with an adapter, so I don't have to do any soldering.Besides - if I decide to solder it, there wouldn't be a yellow cable to connect anyways.

author: Ian.M
author_rank: Super Contributor
timestamp: September 15, 2023, 11:13:34 am
content: Get the two wire version and use one of these:https://www.amazon.de/Poppstar-Adapter-Female-Terminal-Lighting-Black-Green-Metal/dp/B084RHH8LC/If you've already bought the three pin version, either cut the plug off it or get a RC servo extender cable and cut the female plug off that.

author: BavaroneMUC
author_rank: Newbie
timestamp: September 15, 2023, 01:39:24 pm
content: Very nice, that looks like a good solution.Haven't bought any of the components, yet.Thanks, I appreciate it.

author: sparkydog
author_rank: Regular Contributor
timestamp: September 15, 2023, 05:38:03 pm
content: What Ian said. 🙂OTOH, 9€ is expensive; that's definitely the part you want, but look around for other sellers. For that matter, if you haven't bought the wall wart yet,https://www.amazon.com/dp/B07VQHYGRDcomes with the required adapter, and that's just what popped up first; there might be even better options. Enough people are apparently using these to power LED strips that it's not uncommon to find the female adapter bundled with something else, and that will probably be your cheapest option.

author: Ian.M
author_rank: Super Contributor
timestamp: September 15, 2023, 06:28:49 pm
content: A cheapskate would use a salvaged 12V 'wall wart' PSU from the eWaste, and cut the plug off it to use a 'chocolate' block (screw terminal block) or Wago connectors to join the wires.

author: alligatorblues
author_rank: Regular Contributor
timestamp: September 17, 2023, 03:46:27 pm
content: I have a TEC cooler, and I needed to slow down the fan on the heat sink. I just stuck a resistor in the line.