RUNCCI-YUN 2pcs DC 12v PWM motor speed controller,1.8V 3V 5V 6V 12V 2A Speed Adjustable Switch Module, Variable Voltage Regulator Dimmer Governor Switching Build with LED Indicator and Switch Function

5V usb supply into this module then a 12v fan yields great results. Controller and knob moves smoothly and mounts easily with included nut. With this simple setup, the fan is able to operate through a full range of RPM'. LED power indicator built into the PCB is nice and bright. It is easily visible when I poked a pin hole next to it and works nicely with a blob of semi-transparent sealer / glue to act as a diffuser. Good value items for your home project. Have since acquired more.

Awesome little module that handles SS well, great for controlling small fans/motors. There could be two minor improverments: 1) The led indicator is SMD, in a weird location next to the pot (looking down on the board). Great as an indicator when testing but useless if mounting in a case. If there was headers for an LED is would be better. 2) The terminals are pre-soldered to the board - again ideal for quick/ease, however when using the board in a case/perm fixture I would de-solder this in fav of soldering the connections directly to the board. You find lots of modules come with the header terminals but you have the option of soldering. Apart from that it works really well, extremely well for the price!

Works very well. Beware, the connection markings are underneath the board, so bear in mind when locating

Nice well made speed controllers, good smooth pot and solid terminal block

Worked perfectly really easy to use and I was able to screw it into a suitable place easily. Also low profile enough to quietly fit into my set up

Built quality is OK. Price is good. Not sure why they need to ship 2 as its a bit of a waste but I guess it means I've got a spare. FYI there is only one cable shared between the two units, not that it should matter... cut it etc... ;) But real issue is it only provided 7.9 (ish) to 12.4 Volts. So rather than "Duty cycle adjustable 0%-100%" I would say its "64%-100%" and so I'm giving it 64% out of 5 stars... I say "ish" because the DC voltage was rapidly fluctuating between 7.8 and 8 suggesting its not stable. However for my application which was to drive a silent fan in an extractor assembly it was adequate and the price is peanuts. But with hindsight I'd go for a more expensive one that's proven to do the 0-100% range.

Makes a handy speed controller for a small model railway. I'm sure there would be many other uses as well

Well made and work well