This 12-30VDC 7A PWM DC Motor Speed Controller makes it easy to adjust the speed of a DC motor using any power supply between 12V and 30V. Simply turn the on-board potentiometer to smoothly control the motor's speed from 5% to 100% duty cycle — no external components or programming required. The built-in On/Off switch (integrated into the potentiometer) lets you power the module on and off with a simple click. With support for up to 7A continuous current (10A peak) and built-in over-current, over-temperature, and short-circuit protection, this compact controller is a reliable choice for a wide range of DC motor projects.
⭐ Features
- High Current Capacity – Handles up to 7A continuous and 10A peak current for demanding DC motor applications
- Wide Voltage Range – Works with any DC power supply from 12V to 30V
- 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)
- Built-in Protection – Over-current, over-temperature, and short-circuit protection for safe, reliable operation
- Power Indicator LED – On-board LED illuminates when the module is powered
- Compact Size – Only 50mm × 32mm × 16mm (1.97″ × 1.25″ × 0.62″) excluding potentiometer shaft, 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 | 12–30 VDC |
| Maximum Continuous Output Current | 7A |
| Maximum Peak Output Current | 10A |
| PWM Duty Cycle Range | 5%–100% (adjustable) |
| Control Method | On-board potentiometer with integrated On/Off switch |
| Protection | Over-current, over-temperature, short-circuit |
| Power Indicator | On-board LED |
| Dimensions (L × W × H) |
50mm × 32mm × 16mm (1.97″ × 1.25″ × 0.62″) 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 12V and 30V. 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 7A continuous (10A peak).
- Do not exceed 30V or 7A continuous, 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 (12V–30V) 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 |
| Motor does not spin | Over-current or short-circuit protection triggered | Disconnect power, check motor wiring for shorts, reduce load, then reconnect |
| Power LED does not light up | No power reaching the module | Verify your power supply is on, wires are secure, and voltage is within 12–30V |
| 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 7A | Reduce the load on the motor, improve ventilation, or use a controller rated for higher current |
| Module shuts off unexpectedly | Over-temperature protection activated | Allow the module to cool down, ensure adequate airflow, and verify the motor's current draw is within the 7A limit |
💡 Project Ideas
- Variable-speed fan – Control a 12V or 24V DC cooling fan for workbench ventilation or electronics enclosures
- LED dimmer – Dim a 12V or 24V LED strip light (within the 7A 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 DC water pump for aquaponics, hydroponics, or fountain projects
- Drill press or rotary tool – Add variable speed to a DC-powered drill or grinding tool
- Conveyor belt – Control the belt speed on a hobby or educational conveyor system
- Electric scooter or go-kart – Regulate motor speed on a small 24V electric vehicle (within current limits)
- Winch or hoist – Control the speed of a small DC winch for lifting or pulling applications
🛒 Where to Buy the 12-30VDC 7A PWM DC Motor Speed Controller
You can purchase the 12-30VDC 7A PWM DC Motor Speed Controller directly from Envistia Mall:
12-30V 7A PWM Motor Controller
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.