Fan control module, temperature sensor, PWM, 12V, 0.8A

Fan speed control module using PWM (Pulse Width Modulation) speed control method and a temperature probe, for cooling management in electronic and industrial systems. Powered by  at 12V DC, being compatible with 12V fans and automatically adjusts the fan speed depending on the temperature, using an NTC 50K B=3950 thermal sensor for precise detection of heat variations.

Using the fan in PWM mode is always preferred because it significantly extends their lifespan. Rotating the fan at maximum speed, uncontrolled, leads to greater wear, especially of the mechanical components. Using the module involves starting the fan only when necessary and at the right speed.

The sensor is equipped with a clamping ring that allows the probe to be fixed to the element that requires temperature monitoring. The probe is also waterproof.

The module is capable of a maximum output current of 0.8A, and features an LED indicator for operating status and an intuitive interface for setting temperature thresholds, making it suitable for 2- or 3-wire PWM fans.

There are 3 LEDs on the module that indicate the fan rotation speed, on a scale from 0 (no LED) to 3 (all LEDs on, maximum speed).

Using the module without a temperature probe connected causes it to enter Manual mode, meaning the fan speed will be adjusted using the integrated button on the board.

Using the module with integrated temperature probe allows setting the Acceleration Temperature (Tu) and Acceleration Width (Td), which makes it possible to set the speed levels depending on the detected temperatures.

Specifications:

Supply voltage: DC 12V

Maximum output current: 0.8A

Compatible fan: 12VDC

Temperature sensor: NTC 50K B=3950

Sensor cable length: 50 cm

Power cable length: 20 cm

LED indicator: Yes

Fan compatibility: 2 and 3 wires

Dimensions: 49 x 18mm

Connections:

Connectors SIN and SOUTH are connected directly. Normally, the fan transmits its own speed to the controller, which will receive power in the form of PWM. In the case of the module, the signal is ignored by it, but can be transmitted further from the fan to the controller or PC which can then read the speed.

The fan is controlled exclusively through the pins VO+ and VO-, and the power supply is made exclusively on the pins DC12V + and -. A 3-wire or 2-wire fan can be used. The 3-wire fan will have an additional signal wire, which you can route further or not.

Fan connection:

-        Red wire (+) of the fan → to VO+ (12V power supply)

          Black (-) fan wire → to VO- (ground / GND)

Yellow wire (PWM signal) of the fan → DO NOT CONNECT (the controller regulates the speed without speed feedback)

The temperature sensor is mounted on the board in the area marked with the symbol NTC. The polarity is not relevant (the plug only goes in one way anyway) and it can be extended if desired (be careful not to change the resistance of the wire though). By extending, if resistance is added to the temperature reading circuit, the read values can be offset.

The probe will be attached to the area or element that you want to monitor for temperature, using the mounting lug.

Configuration:

Button functions:

          Short press → Increases minimum speed by 5%.

          Double tap → Decreases minimum speed by 5%.

          Long press → Enter temperature settings (Tu).

          In Tu mode, long press → Go to Td setting.

          In Td mode, long press → Saves settings and returns to normal operation.

Button Usage:

The button on the module is used to adjust the fan operating parameters, including minimum speed, acceleration temperature (Tu) and acceleration width (Td).

          Adjusting the minimum fan speed (Po%):

Short press → Increases minimum speed by 5%

Double tap → Decreases minimum speed by 5%

After changing, wait 20 seconds for the settings to be saved.

The indicator LED in the middle will flash rapidly during adjustment and will turn off after saving.

Acceleration temperature setting (Tu):

Long press the button to enter temperature setting mode.

The LED will blink slowly.

One press → Increases the activation temperature (Tu).

Double press → Decreases activation temperature (Tu).

Long press → Save and go to setting the acceleration width (Td).

Setting the acceleration width (Td):

After long pressing, the LED will flash quickly, signaling that you have entered the Td setting mode.

Double press → Increases or decreases the Td value.

Long press → Saves settings and returns to normal operation mode.

Example:

To change the acceleration temperature to 45°C:

Hold down the button → the LED starts flashing slowly.

Press once to increase the temperature or twice to decrease it.

Press and hold again to confirm and move to Td setting.

To increase the minimum speed by 10%

Press the button twice consecutively.

Setting the fan stop strategy:

This function allows you to configure how the fan automatically turns off when the temperature drops below a certain threshold. The module offers three operating modes, allowing the user to choose if and when the fan will turn off completely.

How to activate the stop strategy setting:

Turn off the power and unplug the fan.

Press and hold the setup button and, while holding it down, turn on the power to the module.

Continue to hold the button for 3 seconds until all three LEDs start flashing rapidly simultaneously.

Release the button – the LED indicator will start flashing, signaling entry into the shutdown strategy setting mode.

Short press the button to switch between the three available modes (see table below).

Press and hold the button to save the setting and return to normal operation.

Stop strategy table:

Example:

If the acceleration temperature (Tu) is set to 40°C, the fan behavior will be:

Mode 1: The fan will never stop, even if the temperature drops below 40°C.

Mode 2: The fan will stop when the temperature drops below 38°C (40°C - 2°C).

Mode 3: The fan will stop when the temperature drops below 35°C (40°C - 5°C).

Temperature settings:

The module allows you to adjust the fan speed based on the temperature detected by the NTC probe, using two essential settings:

          Acceleration temperature (Tu) – The temperature at which the fan starts to increase its speed.

          Acceleration Width (Td) – The temperature range in which the fan speed increases progressively, until it reaches 100%.

Operation:

Below Tu (set temperature), the fan remains at minimum speed (Po).

Once the temperature exceeds Tu, the fan speed begins to gradually increase.

When the temperature reaches Tu + Td, the fan reaches maximum speed (100%).

Acceleration temperature settings (Tu):

This table defines the temperature at which the fan starts to increase its speed. The LED indicators (1, 2, 3) on the module indicate the chosen temperature in binary. Red is on, White is off.

Example: If LEDs 1 and 2 are on (🔴 🔴 ◻), the temperature at which the fan starts to accelerate is 70°C.

Throttle width (Td) settings:

This table defines the range in which the fan speed increases progressively, from Po% to 100%. Red is on, White is off.

Example: If LEDs 1 and 3 are on (🔴 ◻ 🔴), the fan speed will reach 100% after a 40°C increase above the Tu temperature.

General settings for operation:

This table defines the fan operating mode, including minimum and maximum speed, percentage adjustments, and standby status for saving settings.

Example: If LEDs 1 and 2 are on (🔴 🔴 ◻), the fan power will be increased by 5% compared to the initial setting.

Summary of operation:

Choose the acceleration temperature (Tu) – The point at which the fan starts to increase its speed.

Choose the acceleration width (Td) – Define how quickly the fan reaches maximum speed.

Configure other general settings – Adjust minimum/maximum speed and power adjustments.

Configuration example:

Setting Tu = 40°C (LED: ◻ 🔴 ◻)

Setting Td = 10°C (LED: ◻ ◻ 🔴)

The fan starts to accelerate at 40°C and reaches 100% at 50°C.

Content:

1 x Control module

1 x 3-wire cable, 2.54mm at DuPont Mom

1 x Temperature probe