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Pulse-width modulation (PWM) controls a signal by changing how long each repeating digital pulse stays on. That on-time fraction is the duty cycle; in many power-control circuits, changing it changes the average power delivered to a load.
What is PWM duty cycle?
A PWM waveform repeats an on-and-off cycle. Duty cycle is the share of each cycle that the signal is on, usually expressed as a percentage:
Duty cycle = on-time ÷ period × 100%
For example, if the signal is on for one quarter of every cycle, its duty cycle is 25%. The same period can instead contain a 50% or 75% on-time:
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These sketches show relative on-time, not a particular voltage or frequency. Microchip defines the pulse width as the time the signal remains high. Microchip Technology’s PWM overview describes the period as the time between successive rising edges.
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- ♥Product parameters: 1. Working voltage: DC9V~60V, input anti-reverse connection protection 2. Rated current: 12A, maximum current 20A 3. Maximum power: 500W 4. Operating frequency: 1KHz~99KHz adjustable, 1KHz step, default frequency 20KHz, accuracy about 1% 5. Duty cycle: 0-100%, 1% step 6. Product size: 79mm*43mm*26mm Installation hole size: 39.3mm*76.5mm 7. Product weight: 43g (bare weight), 65.5g (with packaging) 8. All settable parameters are stored when power is off.
- ♥ Wiring Instructions: ① Motor start and stop indicator: start light on, stop light off ②Digital tube: display the duty cycle of motor adjustment, upper and lower limit of duty cycle and frequency ③Digital tube: Display the motor adjustment duty cycle, upper and lower limit of duty cycle and frequency" ④It can be connected to switch signal or 3.3V level signal to control the start and stop of the motor ⑤ Motor output positive and negative poles Power input positive and negative
- ♥ Digital encoder knob operation: ①In the default interface: (the default display is the duty cycle) Short press: switch the motor on and off. Press and hold for 10 seconds: enter the setting interface. Counterclockwise rotation: the duty cycle decreases. Clockwise rotation: increased duty cycle.
- ♥②Setting interface: Short press: select the setting parameter, the setting parameter can be switched between ON-OFF, duty cycle lower limit, duty cycle upper limit, and operating frequency. ON-OFF is the default module power-on normally open or normally closed, the lower limit of the duty cycle is displayed in the form of "L" + two digits, and the upper limit of the duty cycle is displayed in the form of "H" + two digits or "100", the operating frequency Displayed in the form of "+two digits".
- ♥STOP port on the back: It can be connected to external switch buttons or a 3.3V level. Do not use it in complex electromagnetic environments, and there is no relevant protection inside the circuit. (Note that the external switch should use a self-reset button or key, press it once to turn it on, and press it again to turn it off; it cannot realize the function of always closing the output to open, and not closing the output to close).
How are PWM period and frequency related?
The period is the duration of one full cycle; frequency is the number of cycles per second. They are reciprocals: period = 1 ÷ frequency. A 1 kHz PWM signal therefore has a period of 1 millisecond, as in Microchip’s example. Duty cycle and frequency describe different properties: duty cycle sets the on-time share within each cycle, while frequency sets how often cycles repeat.
How does PWM control a motor or dim an LED?
In common power-control arrangements, a switch rapidly turns a supply on and off. Increasing duty cycle keeps the switch on for a larger share of each cycle, which usually increases average power delivered to the load. PWM is used in motor control, LED lighting, and power supplies.
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- 【Motor Speed Controller】Ultra-low voltage dc motor governor with the chip model: NE555; Potentiometer with switch function; Use a 2A resettable fuse to protect the controller; Power-on indicator. This controller can continuous change device working current and completely cut off.
- 【High Performance】Input supply voltage DC 1.8V-12V. Maximum continuous output current 2A. Maximum output power 30W. Duty cycle adjustable 0%-100%.
- 【Secure Enough】The speed controller is equipped with a self-recovery fuse. When the current is too large, the fuse is automatically disconnected. After cooling, the fuse is automatically restored.
- 【Pay Attention】①Please connect this DC controller to DC power supply. Never connect directly to household 220V AC power supply, or it will be damaged; ②Don't power supply larger than 15V. ③This is a 2A high current governor, which can't drive larger than 0.5A continuous current / the 775 motor / children's car motor. Please confirm again before purchasing.
- 【Widely Applications】It is suitable for the speed regulation of DC motor, fan, fish tank oxygen pump and other products in DC1.8V--12V.
LED brightness
A PWM-driven LED receives repeated pulses. Changing their duty cycle changes the drive over time and can change perceived brightness, provided the LED driver and circuit are designed for PWM control. The exact current and brightness response depend on the driver and circuit; duty cycle alone does not guarantee a particular output voltage.
Motor speed
For a motor drive that supports PWM, duty cycle can adjust the power supplied to the motor and thus influence speed. The motor’s inductance, drive circuitry, load, and switching frequency affect how it responds. There is no single PWM setting that applies to every motor or controller.
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- WIDE VOLTAGE & GRADED POWER SAFETY — Designed for 7–70V brushed DC motors, this heavy-duty speed controller delivers 1%–100% stepless duty cycle tuning without low-speed stalling. Built with high-voltage MOSFETs and three 100V capacitors, it follows strict safety thresholds (12V≤250W, 24V≤350W, 48V≤450W, 60V≤400W, max 30A) to prevent heat build-up. Keeping a 5–10V voltage margin promotes long-term durability for power-hungry ride-on mods, electric go-karts, and custom DIY builds.
- WHISPER-QUIET 12KHZ PWM & HIGH HEAT DISSIPATION — Wave goodbye to high-frequency motor whine and sudden speed jolts. The advanced 12kHz PWM drive circuit ensures smooth acceleration and vibration-free operation at any speed setting. Housed in a rigid aluminum enclosure that dissipates heat rapidly, this controller maintains cool performance during extended sessions on workshop bench tools, agricultural pumps, and marine trolling motors.
- FLEXIBLE MOUNTING & 3-WAY CONTROL SWITCH — Customizing control panels is seamless with the included 15cm (5.9 in) detachable potentiometer ribbon cable. The panel features an integrated Run/Stop/Brake rocker switch for instant halting and control. Ideal for retrofitting RV ventilation fans, golf cart accessories, mini drill grinders, and automated robotics where panel-mounted controls are required.
- FOOLPROOF WIRING & OVERCURRENT PROTECTION — Clear terminal markers prevent costly reverse-polarity damage on the DC input. Motor outputs are non-polarized—simply swap the two motor wires to reverse rotation direction. Equipped with an onboard power status LED and a replaceable inline fuse, it guards your equipment against unexpected current surges during sudden load spikes.
- REAL-LOAD TUNING & POWER CUTOFF NOTICE — Engineered for accurate real-world feedback. In PWM controllers, measured no-load output voltage equals input voltage; real-time speed adjustment and voltage drops must be measured under an active motor load. Note: Setting the potentiometer knob to the lowest position sets the motor to minimum speed but does not cut off power completely; disconnect the main power supply for a full shutdown.
Does a PWM pin produce an analog voltage?
Not by itself: the raw pin produces a digital pulse train, not a steady analog voltage. An RC low-pass filter can average the pulses into an approximate voltage. Microchip describes this as a low-cost digital-to-analog conversion approach, but the filtered result is an approximation whose behavior depends on the filter and PWM signal.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What are edge-aligned and center-aligned PWM?
These names describe how pulses are positioned within a timer’s cycle. Microchip contrasts edge-aligned PWM, which it associates with simple configuration, fast response, and higher resolution, with center-aligned PWM, which can be useful for reducing harmonics in some applications. Those are implementation-specific considerations, not a universal ranking.
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- Adjustable duty cycle: 0%-100%
- Maximum output power: 30W
- Maximum continuous output current: 2A
- Input voltage: DC 2.2V-15V; output voltage: 1.8V-15V
- Equipped with a 2A self-recovery fuse, which will automatically disconnect if the current is too large, and will automatically recover after the fuse cools down
When choosing a configuration, consider the required duty-cycle resolution, frequency, response, harmonic behavior, and the hardware capabilities of the specific microcontroller. Consult its datasheet and the requirements of the load before selecting settings; no frequency or resolution is right for every application.
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- Mini DC 6-35V 5A PWM Motor Speed Controller. Wide voltage DC motor speed controller, PWM duty cycle: 1% -100%.
- Mini Style DC Motor Speed Regulator controls the speed of a DC motor by adjusting Pulse-Width-Modulated (PWM).
- Default disconnection of short circuit point, suitable for 5-35V input.
- Operating voltage: DC5V-35V, quiescent current: 0.015A (standby state)
- Mini wide voltage DC motor governor adopts the latest low voltage drive technology, the current is up to 5A, the maximum voltage is 3-35V (3-9V input needs short circuit), and it is equipped with self-recovery fuse, stable performance, also suitable for LED Dimming.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
