STEVAL-IHT001V2 Cold thermostat kit based on AC switches and the STM8S Data brief Features Low-cost solution for spark-free thermostats: No need for a sealed version Low-cost STM8S microcontroller for thermostat control Low-cost capacitive power supply High efficiency: Refrigerator consumption reduction by adjusting and reducing the hysteresis threshold of the temperature Improved efficiency by turning on the defrost resistor only when it s useful and not at each OFF cycle of the compressor (as done in some mechanical thermostats) a light bulb, and optionally, a defrost resistor and a High system immunity: fan, working on 220/240 V , 50/60 Hz mains RMS Overvoltage protected ACS switches: voltage. The thermostat kit is operational with ACST610-8FP for compressor control, 100/120 V RMS 50/60 Hz but the supply capacitor ACS110-7SN for defrost resistor and value must be modified. ACS102-6TA for light bulb and fan The board can operate in an ambient temperature Class A criteria for IEC 61000-4-4 up to range from 0 C to 60 C. above 3 kV levels The exact maximum temperature depends on the Flexibility: power of the loads. For demonstrative purposes a Development: program setting with PC graphic user interface (GUI) has been developed. interface to change firmware variables The connection between the PC and STM8S Industrialization: end-of-production MCU microcontroller, the MCU performing thermostat programming thanks to FLASH, for soft regulation, is achieved through a USB bus. upgrade and efficient MCU stock management As the STM8S is a low-cost MCU without an RoHS compliant embedded USB peripheral, an additional MCU (STM32) has been used as a bridge between the PC and STM8S MCU, for demonstrative purposes Description only. The STEVAL-IHT001V2 thermostat kit provides a robust and low-cost ST solution (microcontroller and AC switches) to control refrigerators, freezers or fridge/freezer combinations. Basic, defrost, and air circulation versions are configurable in order to address the low-end and medium-end cooling appliances market. It allows the control of a single-phase induction motor and October 2012 Doc ID 023175 Rev 3 1/7 For further information contact your local STMicroelectronics sales office. www.st.com 767 *1 67 *1 67 *1 21 877 21 877 6: 6: 6: 21 %877 38 21 877 6+ 21 877 6+ 21 877 6+ 38 B/( (( *5 67 9&& 67 9&& 67 9&& 670 *1 67 *1 B/( (( *5 67 *1 (5 %8== Q)Q) B/( (( *5 3= (5 %8== B/( (( *5 670 9&& B/( (( *5 3, *+7/, DOOLF HW P +0 X) *1*1 1 OOLF 2+0 9 9&& 9 9 6 & 7 6 7 6 6 & & 4 9&& 4 4 4 4 4 4 DOOLF HW P +0 *+ /, *+ /, Schematic diagrams STEVAL-IHT001V2 1 Schematic diagrams Figure 1. Control side schematic 1B & 17 . 673 (0+ 7 B : 2 B 7 +7683 % )) Q Q : +0 ) 03 %7( . ,31 17& 0 B B0 1 & 1 ) Q : 383% 0+ 70( )57( B326,1 26 ()57 7 38+%6 ) (%3 7380 . (726)5 ) 0+: B0 B0 Q 31B05(6625&2,3 1 0+2 58 34 0 B &+,:6 5227 ) 5&2503(662 Q 96B31,= . ,:7&225 6+ Q) Q) +:0 0 B B0 B06 1, 6 ) : 2 2,+7&56: 2 1 DWLHPOO+0 . 67& +2,25: /( /( /( /( /( 725 H: DPW 5 / / +2/5( 6()8 : 1 1 1 1 1 9 ) (5B/( 1, 06B B0 - V 2/7 Doc ID 023175 Rev 3 - - - - 73 - 73 73 73 ) 73 73 &21 ) 5 5 5 5 & & 5 73 ) ) 2 2 5 2 2 Q) & & & 59 & & & X 5,6 73 7373 & & =9 5 5 5 5 2+0 2+0 2+0 5 5 5 2 : F & & 5 ) 1B 2+0 5 - 2+0 5 5 2+0 5 & & 5 2+0 5 2+0 5 5 5 - & & & & Q Q Q