








⚙️ Master your power, control your craft — voltage on your terms!
The AC Variable Speed Controller is a high-performance SCR voltage regulator compatible with 120V to 220V inputs, delivering up to 15A current and 4000W power for resistive loads. Engineered with premium materials like SMD thyristors and aluminum heat sinks, it offers precise voltage adjustment (0-220V) and robust protection circuits for safe, reliable operation. Perfect for managing speed and power in fans, routers, electric motors, and heating appliances, it’s the essential tool for professionals seeking customizable power control without compromising safety.














| ASIN | B0C2VLSVR5 |
| Batteries required | No |
| Best Sellers Rank | #137,861 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #61 in Electrical Motor Controls |
| Customer Reviews | 4.1 4.1 out of 5 stars (159) |
| Display Type | LCD or LED |
| Included Components | controller |
| Item Weight | 1.08 pounds |
| Item model number | SD-4000W-01 |
| Manufacturer | SDRGEEK |
| Product Dimensions | 4.49 x 3.94 x 3.15 inches |
C**R
Excellent Variac Controller
Bought this for use with a 240v griddle from the EU. The griddle has no temp control and 220v was too hot. Using this controller, we were able to adjust the voltage and thus the griddle temperature to just the right degree, which is about 185v for our task. I wasn't sure if this would work, but it works very well.
E**E
Works great on our old Kitchen Aide mixer.
Our old Kitchen Aide stand mixer speed switch quit working. Bought this variable speed controller and love it. Works great and much cheaper than a new mixer.
J**N
Good tool to work with I recommend it
It works great I'm using it on my drill press which works excellent
S**M
Problem Solved!
I had some issues getting this working, the way I wanted it to. But working with the manufacturer I was satisfied with the solutions they provided.
D**D
Feels cheaply made, but works.
Got this and was surprised at how lightweight it is. Weight-wise, it feels like the controller is empty, and feels like it was made very cheaply. Was skeptical, but plugged it in to run a large shop fan. This fan has 2 speeds - tropical force and hurricane force winds! Works well for outside and a large shop, but we wanted to use it indoors when doing repairs around the house as well. Hooked this controller up, and it definitely slows the fan speed down. The fan doesn't even start to work until the dial on the controller is at about 60% (less than that the fan does nothing), and goes up from there. When using the controller the fan speed never gets to full speed, even at 100%. Not a problem because if we want the fan to run at full speed, we just unplug the controller, and use the fan as-is. We wish the speed control was better at controlling the fan between 0-100%, but at least it does make the fan usable indoors, whereas it wasn't before. With the build quality, I'm not really sure how long it will last, but time will tell.
R**T
Doesn't control anything
Didn't work from the get-go. No matter where the dial is set, the output voltage is always the same as input. I didn't have high hopes due to the low price anyway. Returned to Amazon for refund.
B**T
Great fan speed controller
I have two Westinghouse table fans from the 1950s. They move a lot of air but they tend to be a bit noisy. When I want a lot of moving air or I want white noise for a sleep, those fans are great. For TV I want much less airflow and much less noise. This controller works perfectly to slow the fan, reduce the air and cut the noise dramatically. I can use the ON/OFF switch without changing the speed setting and the fan returns to the preset speed from the night before. That's just what I wanted. The watt meter on the controller does not show what wattage of this fan. I don't know why and I really don't care. The controller does what I want it to do.
C**Y
Very good
Works exactly as advertised. Very good motor controller and temperature controller.
Trustpilot
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