BN-LINK Variable Fan Speed Controller, Plug-in Electric 3 Speed Regulator Adjuster Cordless for Duct Inline Exhaust Vent Blower, Ventilation Fans, AC Motor Speed Controller, 125V, 4.8A, 600W

Works great. I use it on a 3" variable speed bench grinder the switch had gone out on and it worked flawlessly. Saved me time and money.

I have a vintage 1980’s Dremel I inherited from my grandmother-in-law that I enjoy using and being reminded of her, but it doesn’t have variable speed control. Some of the tasks I use it for I need to reduce the speed to prevent burning of the workpiece. This rheostat allows me to dial the speed down and still use my old gem.

My ceiling fan only has 1 speed - hurricane. This little guy was able to bring it down to a more comfortable speed.

I purchased this to slow down a fan that was just too strong and noisy even on the lowest setting. And it works to a degree - maybe as advertised.The main complaint I have is that it doesn't reduce the voltage as much as I'd like. I completely understand that slowing down an electric motor too much isn't good and can cause the motor to overheat. I get it. But this controller seems to barely make a difference.Additionally, maybe not an issue of the controller, but as I decrease the dial, the fan motor actually gets louder - which defeats my purpose.Bottom line, this may work in some applications, but not for what I was needing.

My through wall vent fan motor died, and I could not find a variable speed replacement that would fit the hole, so my son and I made it a project and sourced a motor that would fit and this external variable speed adjuster. They worked great for less than half the price what a new fan (had I been able to find one) would have cost. As a bonus the speed knob is now at a much easier to reach location than it was before!

WORKS - but be aware this changes the current to square wave WITH HUM !It works, but I had hoped it was adequately designed to NOT induce the huge HUMMING noise these kinds of controls almost all seem to do, minus the really high buck ones. The modified square wave electrical signal that comes OUT of this control that allows your fan to run with less RPM - makes ANY fan HUM!!In many aps, that's not a problem, so this is your unit!! Who cares about a little hum in a body shop, welders area, barn, etc?BE AWARE --- you run ANY fan or motor below a certain RPM and you WILL BURN IT UP!!! Nothing good happens from that!Turn your fan ALL THE WAY up to HIGH, .......... THEN use your new control to reduce speed. That's how ya do it, but they don't tell you so. Trust me, and the other experts who know this is what works. Not ideal to set your fan to the LOW of 3 settings - THEN use your control to lower it more. You can try that, but make sure nothing is getting hot - wires, controls, plugs!!! It "may" harm your fan motor if you go too low, too long~!

Used for a Honeywell 3 speed fan.

It actually ended up failing internally, I found the fan going full blast and when I went to unplug it the device was so hot I am amazed it wasn't on fire. Definitely dangerous. Use on tiny fans only. Any fan that is large just buy a different higher Amp rated device.