Mini 3A PWM 12V DC Fan Speed Controller – 4-Wire Regulator

Mini PWM DC Fan Speed Controller – Compact & Precise

Take full control of your 12V four-wire PWM fans with this compact, high-quality Mini 3A PWM DC Fan Speed Controller. Built for electronics enthusiasts, PC builders, and DIY tinkerers, this tiny module (just 2.5 × 2 cm) delivers smooth, adjustable fan speed from 0% to 100% output — all from a simple potentiometer twist. It features an onboard on/off switch, stable PWM signal at 5V/25KHz, and a standard 2510-4P output connector compatible with most CPU and chassis fans.

Made in China.

Key Features

• Adjustable Speed Control: Potentiometer dial adjusts PWM output from 0% to 100% — turn counterclockwise to minimum, clockwise to maximum
• Built-In On/Off Switch: Easily cut power to the fan without unplugging anything
• Start Speed Trimmer: Onboard mini adjustable resistor lets you set the minimum startup speed independently
• Reverse Fan Compatibility: Short the (PF) solder point to reverse the PWM signal direction — supports reverse-timing fans
• Standard Connector: 2510-4P output (2.54mm pin spacing) fits conventional CPU and chassis fan sockets
• Flexible Input: Red/black wire or 2510-3P input options
• Low Idle Draw: Circuit board consumes less than 20mA when no fan is connected
• Durable Metal Construction: Sturdy build in a compact, lightweight form factor

Specifications

Important Usage Notes

• This controller is designed exclusively for 12V 4-wire PWM fans (CPU fans, chassis fans). It cannot control 2-wire or 3-wire fans.
• Always match the fan voltage to the supply voltage (8–15V range).
• Observe correct polarity (positive/negative) before connecting power.
• When shorting the (PF) pad for reverse fans, always disconnect power first to avoid component damage.
• Colours of the physical item may vary slightly from product images due to monitor brightness and lighting conditions. Minor dimensional tolerances may apply.

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For more information on electrical safety standards and best practices when working with DC electronics, visit the U.S. Consumer Product Safety Commission (CPSC).

Frequently Asked Questions

Q: What type of fans is this PWM DC fan speed controller compatible with?

A: This controller is designed specifically for 12V 4-wire PWM fans, such as standard CPU coolers and PC chassis fans with a 2510-4P connector and 2.54mm pin spacing. It is not compatible with 2-wire or 3-wire fans, as those do not use a PWM signal for speed regulation.

Q: How do I adjust the fan speed using this controller?

A: Simply turn the potentiometer dial — rotate counterclockwise to reduce fan speed (down to 0% / off position) and clockwise to increase speed up to 100% maximum output. There is also a small onboard trimmer resistor that lets you set the minimum startup speed independently, giving you fine-tuned control over how your fan behaves when first switched on.

Q: What does the (PF) solder point do, and when should I use it?

A: The (PF) pad reverses the direction of the PWM signal. If your fan speeds up when you turn the dial counterclockwise (i.e., the adjustment direction is reversed), your fan uses a reverse-timing PWM protocol. Shorting the (PF) pad with solder inverts the signal so the dial behaves as expected. Always disconnect power before soldering to avoid damaging the module or the fan.

Q: Can this controller work with voltages other than 12V?

A: Yes — the module operates within a range of 8V to 15V DC, though it is optimised for 12V. Make sure your fan's rated voltage matches your power supply voltage. The maximum supported fan current is 3A; if your fan draws more, run a separate power lead directly to the fan and use this module only for the PWM signal wire.