AN1353 Datasheet - STMicroelectronics

Introduction
In this document, we explain the software of an Electronic thermostat bread board. The demonstration kit has been developped by STMicroelectronics and is available under THERM01EVAL reference.
This board illustrates the operation of a low cost electronic thermostat for 220-240V 50Hz cold appliances, including STMicroelectronics ACS102-5TA, ACST6-7ST and ST62 devices.

The microcontroller will ensure four functions:
● Temperature regulation (temperature capture through NTC resistor + Hysteresis
   regulation).
● Compressor monitoring: the motor is controlled depending on fridge temperature. To
   start it, the starting triac Ts and the run triac Tr are triggered simultaneously for 500ms.
   Then, only the run triac will continue to conduct.
● Overcurrent detection: this is based on the measure of the peak current using a shunt
   resistor. During the one second (500 ms+500 ms) of starting transient, this routine
   does not run.
● Internal light bulb control.