W1209 DC12V digital thermostat relay

The W1209 Thermostat Temperature Control Switch is an incredibly inexpensive yet highly functional thermostat controller.

With this module (HCTHER0006), you can intelligently control the power to most types of electrical devices based on the temperature detected by the included highly accurate NTC temperature sensor.

Although this module has a built-in microcontroller, no programming knowledge is required.

3 tactile switches make it possible to configure various parameters, including on and off trigger temperatures.

The onboard relay can switch up to a maximum of 240V AC at 5A or 14V DC at 10A. The current temperature is displayed in degrees Celsius via the 3-digit seven-segment display and the current relay status by a built-in LED.

The transparent acrylic housing can be ordered separately (OT3704)

Display color: RED

• Temperature control mode: ON / OFF
• Temperature range:-50-110
• Resolution When the temperature is 0.1, the resolution is -9.9 ~ 99.9, the other temperature segment is 1
• Control accuracy: 0.1
• Hysteresis accuracy: 0.1
• Refresh rate: 0.5S
• High temperature protection 0-110
• Supply voltage: DC 12V
• Static current: ≤ 35MA, pull current ≤ 65MA;
• Output voltage: DC 12V
• Output power: 10A relay
• Measurement input: NTC (10K 0.5%) waterproof sensor
• Environmental requirements: -10 ~ 60 Humidity 20% -85%
• Size: 48x40mm (LxW)

Delivery includes:
1x Relay board with display and buttons
1x Temperature sensor with approx. 50cm wire

Manual W1209

The board comes with three tactile buttons to set the temperature: Set, + and -.

Hold Set to open the menu, the display shows P0.

Use + and - to scroll through the different menus (see table below).

Press Set to select a menu option.

Use + and - to change the value for that option.

Press Set again to save the setting and return to the menu.

Hold both + and - for a while to return to the factory settings.

After 5 seconds, the circuit board returns to thermostat mode.

 *Hysteresis:

Hysteresis refers to the difference in temperature values between the moment a device (such as a thermostat) turns on and the moment it turns off.

For example, if the desired temperature is set to 25°C and the hysteresis is set to 2°C, the thermostat will turn the heating on when the temperature drops to 23°C and turn the heating off when the temperature rises to 27°C. Hysteresis helps prevent the device from switching on and off frequently with small temperature fluctuations, which can be more energy-efficient and can extend the device's lifespan.

In other words, hysteresis sets a margin within which the device does not respond to small changes in temperature in order to prevent unnecessary switching.