W1209

This is XH W1209 12V Digital Temperature Controller Module W/ Display and NTC Temp Sensor.

W1209 Mini thermostat Temperature controller is low-cost 12V Temperature controller with 7-segment display and 3 switch keypad for setting temperature and other parameters. The module features an NTC thermistor temperature sensing and has an accuracy of 0.1 C.

The XH W1209 digital temperature controller Module W/ Display and NTC Waterproof Temperature Sensor is an incredibly low cost yet highly functional thermostat controller. With this module, you can intelligently control power to most types of electrical devices based on the temperature sensed by the included high accuracy NTC temperature sensor.

We can display the current temperature in degrees Centigrade via its 3 digits seven-segment display and the current relay state by an onboard LED.

Displaying the current temperature

The thermostat will display the current temperature in °C by default. When in any other mode making no input for approximately 5 seconds will cause the thermostat to return to this default display.

Setting the trigger temperature

To set the trigger temperature press the button marked ‘SET’. The seven-segment display will flash. You can now set a trigger temperature (in °C) using the ‘+’ and ‘-‘ buttons in 0.1° increments. If we didn’t press any buttons for approximately 2 seconds the trigger temperature will be store and the display will return back to the current temperature.

Setting the parameters

To set any parameter first long press the ‘SET’ button for at least 5 seconds. The seven-segment display should now display ‘P0’. This represents parameter P0. Pressing the ‘+’ or ‘-‘ buttons will cycle through the various parameters (P0 to P6). Pressing the ‘SET’ button whilst any of these parameters are displayed will allow you to change the value for that parameter using the ‘+’ and ‘-‘ buttons. When finished setting a parameter press the set button to exit that option. If no buttons are pressed for approximately 5 seconds the thermostat will exit the parameter options and will return back to the default temperature display.

Setting the cooling or heating parameter P0

The parameter P0 has two settings, C and H. When setting to C (default) the relay will energize when the temperature is reached. Use this setting if connecting to an air-conditioning system. When set to H the relay will de-energize when the temperature is reached. Use this setting if controlling a heating device.

Setting the hysteresis parameter P1

This sets how much change in temperature must occur before the relay will change state. For example, if set to the default 2oC and the trigger temperature has been set to 25oC, it will not de-energize until the temperature falls back below 23oC. Setting this hysteresis helps stop the thermostat from continually triggering when the temperature drifts around the trip temperature.

Setting the upper limit of the thermostat parameter P2

This parameter limits the maximum trigger temperature that can be set. It is useful as a safety to stop an excessively high trigger temperature from accidentally being set by the user.

Setting the lower limit of the thermostat parameter P3

This parameter limits the minimum trigger temperature that can be set. It is useful as a safety to stop an excessively low trigger temperature from accidentally being set by the user.

Setting temperature offset correction parameter P4

Should you find there is a difference between the displayed temperature and the actual temperature; (for instance, if the temperature probe is on a long run of cable) you can make minor corrections to the temperature reading with this parameter.

Setting the trigger delay parameter P5

To reach trigger temperature this parameter allows for delaying switching of the relay. The parameter can be set in one-minute increments up to a maximum of 10 minutes.

Setting the high-temperature alarm parameter P6

Setting a value for this parameter will cause the relay to switch off when the temperature reaches this setting. The seven-segment display will also show ‘—‘ to indicate an alarm condition. The relay will not re-energize until the temperature falls below this value. The default setting is OFF.