I have used these before, they work great on controlling 12v or 24v motors, I installed these in my RV, one in the shower fan motor to slow it down and one on my range hood. The RV 12v range hoods only have a couple fixed speeds and both very noisy. Installing one of these just makes the range hood so much more useable and removes most of the excess noise. Still move a lot of air to the outside without make a huge amount of noise. They should install these at the factor as a standard item. I have a new overlander being built and i am again installing these items in the range hood and fans.Very inexpensive and easy to install, well built for what the cost are. I do recommend these.

These work fantastic as led dimmers and absolutely no LED flicker at low light levels. There is a tab on the back you may not notice which is if you're using lower voltages you want to short out those two tabs with your soldering iron when dimming or controlling lighting loads between 3 to 15 volts but otherwise you don't need to short them. You can also remove the screw down terminals quick and easy and these things will fit in a very compact location. They also run very cool. I'm ordering more.

These are good value mini speed controllers. They're not the most fancy nor do they support all of the operations under the sun but they do what I need them to do. What is obvious on this is that there is no schematic and the ratings that it is stating I can so far not back up and therefore I docked a star. While it works for my use case (powering a motor at variable speeds), I am not certain that this is going to hold the test of time.

Suppose you have a small DC motor, connected to a fixed power supply, whose speed you’d like to vary a little bit. Alternately, suppose you had a fixed supply connected to a lamp, and you’d like the option to dim it. In the old days, you’d insert an appropriate resistor in the line, causing a voltage drop and reducing the current in the loop. Yes, the motor would run more slowly (and the lamp would dim), but that resistor dissipates a lot of energy as heat. Besides being inefficient, this kind of wastefulness can be a big problem in a battery-operated application, for example.Another approach to control is to insert an electronic switch, and then turn the switch on and off so fast that they eye can no longer perceive the flicker. You could flick the switch symmetrically—50% of the time on, and 50% of the time off—but you don’t have to. In fact, if you vary the ratio of on-time to off-time, you can make a connected motor run at any speed and a lamp light to any intensity you want, from fully-off to full-throttle. This scheme is called “pulse width modulation.” Oh, and because there is no dropping resistor... just an electronic switch that at any instant is either fully on or fully off... the scheme offers fine control without the wastefulness that a resistor causes.This offering by DORHEA is a small pulse width modulation control unit. It consists of a small printed circuit board hosting a pot, two terminal blocks, and a relative handful of small surface-mount components. The idea is that you connect your power supply to two terminals, your load (a small D.C. motor or lamp, for example) to the other two, and then by adjusting the pot, you can control the relative speed of the motor or intensity of the lamp.For testing purposes, I connected one of the units I received to a 24-volt DC power supply, and loaded the board with an automobile tail lamp that draws about 9/10 of an amp at 12 volts. In the far counterclockwise position, the control pot is off, and no power is delivered to the lamp. When I advanced the pot slightly in the clockwise direction, a switch was heard to click, and small amounts of power were delivered. Dialing the pot up and down allowed me to control the lamps brilliance to any desired level. So... the product basically works.That said, while cheap Chinese-import electronics have been a real boon to hobbyists and ham enthusiasts alike, I find myself routinely vexed by the puzzling (and sometimes absurdly optimistic) specifications attached to these products.For example, the seller claims input voltages of “... DC-DC 5V-35V + DC-DC 4.5V-35V...” What in the world does that mean? One of the accompanying photos describes a shunt that can be installed that lowers the board’s operating range to 3-15 volts, but that doesn’t match either of the first two specifications. So what gives?I pulled up the data sheet on the FET (switching element) used by this board, and it claims a MAXIMUM drain-to-source voltage of 30 volts. Now, I suppose, if this is a low-side driver circuit (I don’t know, because the seller doesn’t supply a schematic) one might argue that the FET should never see full supply-rail so long as a load has been installed. But if you were running above 30 volts and a short developed in the load, it seems likely you’d blow up the FET even before the circuit’s “resettable fuse” could trigger. Again... I’m confused... Is this a bad design or are the specifications (above) misstated?Here’s some more gibberish: The description text reads, in part, “... Mini 12V 5A 2A 90W PWM Motor Speed Controller.” Twelve volts time 5 amps is 60 watts, not 90, so where does the “90W” number come from?Another thing, I ran that automobile tail lamp (as described above) for 20-30 minutes. The FET got noticeably warm, and depending upon where I had the pot set, it could get unpleasantly hot to the touch. Because of the small size of the PCB, there is very little effective heat-sinking for that component. Given that the power in my entire system was no greater than 24v x 0.89 amps = 21.4 watts, it seems highly doubtful to me that this circuit would run at a reasonable temperature at the claimed “90 watts.” For that matter, I’m not sure it would run sufficiently cool at 60 watts.I wish Chinese electronics manufacturers would design to specification “X”, and then advertise the specifications at 1/2-X. That would provide a 2-to-1 safety margin and guarantee expected performance under all conditions. Instead, we get a mish-mash of confusing numbers, pie-in-the-sky, and good intentions. The latter is probably still acceptable for hobby use and science-fair projects, but it really precludes the use of these kinds of modules in any serious project... which is a shame.I have some applications in mind for them. Personally, I won’t be running them above 24 vdc (better still, at 12 volts), nor will I load them in excess of an amp or so. Within the confines of that operating envelope, there is probably enough margin in this circuit’s design that I can reasonably expect reliable performance and longevity, without self-destruction.Your mileage may vary.

These speed controllers are capable of performing within their advertised specifications. While they do handle the rated voltage and can deliver the rated current, I have found that the controllers often limit the rate of power increase; if, for instance, you were to crank the knob under load, the output will slowly and gradually be brought up to your desired output. With that being the case, I would not recommend these controllers for applications where you want the ability to quickly increase or decrease the output.Overall, these controllers are still great for little projects, and for 95% of things, should do the trick. For this reason, I feel a 4/5 star rating is justified.

I like the little board I have used in several of my projects and it's a good price I really happy with the purchase

I haven't tested them under load yet, but for 7 or $8, they're a great tinkering value and don't need any soldering. 5 stars on initial impressions, will update after further use.

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