AC 0-220V 4000W Motor Speed Controller 40A SCR FR-4 Board
AC 0-220V 4000W Motor Speed Controller — 40A SCR, FR-4 Circuit Board
Take precise control of your AC-powered devices with this high-power motor speed controller. Built on a durable FR-4 circuit board with a 40A-rated silicon-controlled rectifier (SCR), this compact unit lets you smoothly adjust voltage from 0V to 220V — ideal for speed regulation, dimming, and temperature control across a wide range of appliances and tools. Made in Mainland China.
Key Features
- Precision Multi-Turn Potentiometer: Enables smooth, fine-grained voltage adjustment for consistent motor speed control without abrupt changes.
- AC 0–220V Continuously Adjustable Output: Starting voltage of approximately 60V with minimal operational lag, giving you responsive, real-time control.
- 40A Rated SCR Design: A quality silicon-controlled rectifier handles up to 40A — built for high-current loads and demanding applications.
- Two-Way Large Power Handling: Supports up to 4000W maximum power, making it suitable for heavy-duty appliances and industrial-light equipment.
- Built-In Protection: Anti-surge, anti-spike, and RC absorption circuitry protect both the controller and connected devices from voltage transients.
- Series Connection Setup: Simply wire in series with your lamp or appliance — connect to either the live or neutral line for easy, tool-friendly installation.
Specifications
| Input Voltage | AC 220V |
| Maximum Power | 4000W |
| Voltage Regulation Range | AC 0–220V |
| Maximum Current | 40A |
| Circuit Board | FR-4 |
| Dimensions | 6 × 4 × 4.5 cm / 2.4 × 1.6 × 1.8 in |
| Color | Green and Silver |
| Weight | Approx. 75g / 2.6 oz |
Common Applications
- Speed regulation of small AC motors and fans
- Dimming of lighting fixtures
- Temperature regulation of electric furnaces, water heaters, and soldering irons
- Voltage step-down for 110V foreign-made appliances on a 220V supply
How to Use
Connect the controller in series with your load (lamp or appliance) by inserting it into either the live or neutral line at the provided terminals. Important: Always connect your load before attempting to adjust the voltage. Rotate the adjustment knob to achieve your desired output level.
What's in the Box
- 1 × AC Motor Speed Controller (FR-4 Circuit Board)
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Frequently Asked Questions
Q: What types of devices can I control with this AC motor speed controller?
A: This controller works with a wide range of AC-powered devices including small motors, fans, lighting fixtures, electric furnaces, water heaters, and soldering irons. It is also useful for stepping down voltage from 220V to approximately 110V for foreign-made appliances. Maximum supported load is 4000W at 40A.
Q: Do I need to connect a load before adjusting the voltage?
A: Yes — it is essential to connect your load (lamp or appliance) before rotating the adjustment knob. Attempting to set the voltage without a connected load may result in incorrect readings or damage to the controller. Always wire your device in series first, then tune to your desired voltage.
Q: How is this controller installed in a circuit?
A: Installation is straightforward — simply connect the controller in series with your appliance on either the live or neutral line. The two terminal connections make it easy to integrate into existing wiring without complex modifications. No special tools are required for basic setup.
Q: What protection features does this speed controller have?
A: The controller features built-in anti-surge, anti-spike, and RC absorption protection circuits. These safeguards help prevent damage from sudden voltage spikes or transient electrical events, extending the life of both the controller and your connected equipment.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.