W1209 TZT DC 12V Temperature Controller Thermostat
Heat/Cool Digital Thermostat Switch with Display
The W1209 is a digital temperature controller operating on DC 12V, featuring both heating and cooling modes. It includes a built-in thermistor sensor and relay output for controlling devices based on temperature thresholds.
Dual Mode Operation - Switch between heating and cooling modes
Large LED Display - Clear temperature readout with status indicators
Supply voltage is DC 12V only - do not exceed
Use the onboard buttons for easy temperature setting
Ensure relay load does not exceed 10A
Technical Specifications
| Parameter | Value |
|---|
| Supply Voltage | DC 12V |
| Measurement Range | -50°C to 110°C |
| Resolution | 0.1°C |
| Accuracy | ±0.1°C |
| Output Relay | 10A (max) |
| Sensor Type | NTC thermistor (included) |
| Display | 3-digit LED |
= Key Features =
Dual Mode - Heat or cool control selectable
High/Low Limit - Set temperature boundaries
Adjustable Hysteresis - Prevents relay chatter
Calibration Offset Finetune temperature readings
Parameter Lock - Prevent accidental changes
Sensor Included - NTC thermistor ready to use
= Applications =
- Incubators and hatcheries
- Aquarium temperature control
- Refrigerator/freezer monitoring
- Greenhouse climate control
- 3D printer enclosure heating
- Food fermentation projects
Versatile Control - Works with heaters and coolers
Simple Setup Userfriendly button interface
√ NTC sensor included
√ Relay output for load control
√ Clear LED display
Connection Guide
Power connections:
- VCC: DC 12V positive
- GND: DC 12V negative
Relay output:
- COM: Common terminal
- NO: Normally open (closes when active)
- NC: Normally closed (opens when active)
Sensor connection:
- Connect NTC thermistor to sensor terminals
- Polarity not critical
Connect load between COM and NO for activation on reaching set temperature
For cooling mode, use NO; for heating, use NC as needed
Do not exceed 10A relay contact rating
Use appropriate wire gauge for load current
Configuration Guide
Button functions:
- SET: Enter parameter settings
- UP (+): Increase value
- DOWN (-): Decrease value
Parameter list:
- P0: Heating (H) or Cooling (C) mode
- P1: Set temperature
- P2: Hysteresis value (0.1°C to 10°C)
- P3: Calibration offset (-10 to +10°C)
- P4: High temperature limit
- P5: Low temperature limit
Default settings:
- Mode: Cooling
- Hysteresis: 2°C
- Range: -50°C to 110°C
Easy Adjustment - Change settings with buttons
Lock Feature - Prevent unwanted changes
Reliable industrial-grade controller
Used in many DIY temperature projects
√ Includes thermistor probe
√ Pre-calibrated and ready
√ Compact for small enclosures
Operation Modes
Heating mode:
- Relay activates when temperature is BELOW set point
- Relay deactivates when temperature reaches set point + hysteresis
Cooling mode:
- Relay activates when temperature is ABOVE set point
- Relay deactivates when temperature drops below set point - hysteresis
Choose mode based on application need
Set hysteresis to avoid rapid on/off cycling
Ensure load is suitable for relay switching
Use contactor for high-inductive loads
Troubleshooting
No display:
- Check 12V power supply
- Verify polarity
- Avoid loose connections
Incorrect temperature:
- Check sensor connections
- Adjust calibration offset
- Avoid sensor near heat sources
Relay not switching:
- Check mode selection
- Verify temperature threshold
- Avoid relay contact failure
