This DC Motor PWM Speed Controller/Regulator controls the speed of a DC motor using a Pulse Width Modulated (PWM) DC voltage from 6V to 28V with a Duty Cycle fully adjustable from 5%-100% using the onboard potentiometer. It can provide a continuous current of up to 3A to your DC motor or other DC load.
⭐ Features
- Wide Voltage Range – Works with any DC power supply from 6V to 28V
- Up to 3A Continuous Current – Drive DC motors and loads up to 80W
- PWM Speed Control – Smooth, efficient Pulse Width Modulation with 5%–100% duty cycle adjustment
- On-board Potentiometer – Simple turn-dial speed control; no external components needed
- Built-in On/Off Switch – Integrated into the potentiometer (click fully counter-clockwise to turn off)
- Power Indicator LED – On-board LED illuminates when the module is powered
- Compact Size – Only 50mm × 32mm × 16.5mm (2″ × 1.25″ × 0.65″), easy to mount in any project
- Screw Terminals – Secure, tool-friendly connections for power supply and motor wiring
💡 What is PWM?
Pulse Width Modulation (PWM) is a technique that controls motor speed by rapidly switching the power on and off. Instead of reducing the voltage (which can cause a motor to stall at low speeds), PWM delivers full-voltage pulses at varying widths. A wider pulse means more power and higher speed; a narrower pulse means less power and lower speed. This results in smoother, more efficient speed control across the entire range.
📋 Specifications
| Input Supply Voltage | 6–28 VDC |
| Maximum Output Power | 80W |
| Maximum Continuous Output Current | 3A |
| PWM Duty Cycle Range | 5%–100% (adjustable) |
| Control Method | On-board potentiometer with integrated On/Off switch |
| Power Indicator | On-board LED |
| Dimensions (L × W × H) | 50mm × 32mm × 15mm (2″ × 1.26″ × 0.6″) excluding potentiometer shaft |
🔌 Terminal Connections
The module has four screw terminals arranged in two pairs. The labels are printed on the back of the circuit board.
| Terminal | Label | Connect To |
|---|---|---|
| Power + | Power + | Positive (+) lead of your DC power supply |
| Power − | Power − | Negative (−) lead of your DC power supply |
| Motor + | Motor + | Positive (+) lead of your DC motor |
| Motor − | Motor − | Negative (−) lead of your DC motor |
⚠️ IMPORTANT: The Power − and Motor − terminals must not be connected together. They must remain as separate connections. Tying them together will prevent the controller from working properly.
🔋 Power Supply Guidelines
- Use a DC power supply rated between 6V and 28V. The voltage you supply to the module is the voltage that will be delivered to your motor (modulated by the PWM duty cycle).
- Make sure your power supply can provide at least as much current as your motor requires. The module supports up to 3A continuous.
- Do not exceed 28V or 3A, as this may damage the controller or your motor.
- We strongly recommend adding an appropriately rated fuse inline with the positive power supply lead to protect the circuit from short circuits.
💻 Setup & Operation
Follow these steps in order for safe and correct operation:
Step 1 — Turn the Module Off
Rotate the potentiometer fully counter-clockwise until you hear and feel a click. This engages the built-in power switch and ensures the module is off before you make any connections.
Step 2 — Connect the Motor
Attach your DC motor's wires to the Motor + and Motor − screw terminals. Use a small flathead screwdriver to secure the wires. If your motor spins in the wrong direction, simply swap the two motor wires.
Step 3 — Connect the Power Supply
Attach your DC power supply (6V–28V) to the Power + and Power − screw terminals. Double-check polarity — connecting with reversed polarity can damage the module.
💡 Tip: Insert an inline fuse (rated slightly above your motor's expected current draw) on the Power + wire for added protection.
Step 4 — Power On & Adjust Speed
Rotate the potentiometer clockwise past the click to turn the module on. The on-board power LED will illuminate, confirming the module is receiving power. Continue rotating clockwise to increase motor speed, or counter-clockwise to decrease it.
- Fully counter-clockwise (past click) = Off
- Just past the click = Minimum speed (~5% duty cycle)
- Fully clockwise = Maximum speed (100% duty cycle / full supply voltage)
🛠️ Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Motor does not spin | Module is switched off | Rotate potentiometer clockwise past the click to turn on |
| Motor does not spin | Power − and Motor − are tied together | Ensure the ground wires are connected to their own separate terminals — do not bridge them |
| Motor does not spin | Reversed power supply polarity | Check that + goes to Power + and − goes to Power − |
| Motor does not spin | Blown inline fuse | Check and replace the fuse if installed |
| Power LED does not light up | No power reaching the module | Verify your power supply is on, wires are secure, and voltage is within 6–28V |
| Motor spins in the wrong direction | Motor leads are reversed | Swap the Motor + and Motor − wires |
| Motor stutters or runs rough at low speed | Motor may require a minimum voltage to start | Increase the potentiometer setting; some motors need a higher duty cycle to overcome starting friction |
| Module or motor gets very hot | Motor is drawing close to or exceeding 3A | Reduce the load on the motor, or use a controller rated for higher current |
💡 Project Ideas
- Variable-speed fan – Control a 12V or 24V DC cooling fan for workbench ventilation or electronics enclosures
- LED dimmer – Dim a 12V LED strip light (within the 3A limit) for accent or task lighting
- Model trains & RC vehicles – Adjust motor speed for scale-model locomotives or remote-control cars
- Pump speed control – Regulate a small DC water pump for aquaponics, hydroponics, or fountain projects
- Drill press or rotary tool – Add variable speed to a small DC-powered drill or grinding tool
- Conveyor belt – Control the belt speed on a small hobby or educational conveyor system
🛒 Where to Buy the 6-28V 3A PWM DC Motor Speed Controller
You can purchase the 6-28V 3A PWM Motor Controller directly from Envistia Mall:
This user guide is provided for informational purposes only by Envistia Mall. While every effort has been made to ensure accuracy, Envistia Mall makes no warranties or representations regarding the completeness or accuracy of the information contained herein. Use of this product is at your own risk. Envistia Mall shall not be held liable for any damages resulting from the use or inability to use this product. Always follow proper electrical safety practices and local regulations when working with electronic components.