W1209 Digital Thermostat DC12V Compact

Physical size: approx. 48.5 × 40 × 15.8 mm; plastic enclosure. Total weight under 25g. Supports temperature measurement and control from -50°C to +110°C. Resolution: 0.1°C within -9.9°C to 99.9°C; 1°C elsewhere. Accuracy: ±0.1°C for both setpoint and hysteresis. Update interval: 0.5 seconds. Power: DC12V only; static draw ≤35mA, relay coil draw ≤65mA. Output: integrated SPDT relay rated for DC12V loads. Sensor interface: accepts standard 10KΩ ±0.5% NTC thermistors with IP67-rated housings. All settings—including target temperature, differential (hysteresis), and display lock—are adjusted via three tactile membrane buttons. The LED display remains legible under varied lighting, with digits large enough for quick verification at arm’s length. Relay contact rating ensures compatibility with common 12V solenoids, Peltier coolers, resistive heaters, and small DC fans—no additional drivers required. Used extensively in UK-based maker spaces and small agri-tech deployments: propagation trays for seedlings, wormery insulation control, bee hive winter heaters, craft brewery glycol chillers, and retrofitting vintage lab equipment with modern digital regulation—where reliability, simplicity, and CE-compliant low-voltage design matter more than flashy features.