Modern refrigerators are evolving and offering more energy efficiency functions. Quick-chill settings help reduce temperature fluctuation. Dual cooling system often includes two separate cooling circuits to allow the refrigerator and freezer to be controlled separately. Some smart refrigerators even offer multiple independent drawers so that consumers can adjust refrigeration conditions to the precise temperature based on the type of food stored inside. NTC temperature sensors, also known as NTC thermistors, are used to help regulate the refrigeration temperature in each section because they are simple, effective, and accurate temperature sensing elements. THINKING provides a variety of NTC temperature sensors for refrigerators.
The latest refrigerators come with advanced features such as wireless connectivity and touch screens. The increased number of electronics makes associated circuit protection more complex and critical. In addition to temperature sensors mentioned above, THINKING offers a broad line of circuit protection components to protect the complex and sensitive circuits and recommends the following protection technologies for use in the applications.
THINKING’s NTC temperature sensors are perfect for applications in various parts of the fridge including the motor, defrost heater, refrigerator and freezer application. To detect internal temperature, the plastic case type sensor is widely used. The sensing top filled with insulation glue makes the sensor moisture resistant, impermeable, and reliable. Putting reliability as the top priority, the NTC temperature sensor was tested for storage in water (5000 h at +30 °C) and for operation in ice (3000 h at -20 °C). The test results as shown below indicate that the temperature sensor experienced minimal temperature swings in the humid and freezing environment, and the temperature remains stable for thousands of hours. For defrost heater application, the metal case type NTC temperature sensor with stainless steel clip is available for easy installation.
Components on the control board such as MOSFET and ICs are vulnerable, and they are suggested to be guarded by Metal Oxide Varistors (MOV). Some designers may choose TVS diodes to protect the circuits from threat of voltage transients.