Schematic Frost Detector Temperature Sensor
To apperceive whether it is freezing you alone charge to admeasurement the temperature. This has to be done accurately, of course, and accordingly we charge to accept a temperature sensor that we accept some aplomb in. The best has afresh been fabricated for a blazon that we accept already acclimated in abounding antecedent Elektor circuits, the LM35CZ (-40 to 110 °C). This sensor is not big-ticket and generates an achievement voltage that is proportional to the temperature in degrees Celsius (10 mV/°C). Sensor An LM35 is commonly powered from a single-ended ability accumulation and 0 °C corresponds to an achievement voltage of 0 V. It is accordingly not accessible to admeasurement abrogating temperatures with an LM35 in the accepted appliance circuit. It is about accessible to admeasurement abrogating temperatures if its achievement is affiliated to a abrogating accumulation voltage via a resistor. There needs to be a accepted of 50 μA through this resistor (R2 in the schematic). We a...