For further information contact your local STMicroelectronics sales office.
October 2012 Doc ID 023175 Rev 3 1/7
7
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)
■High system immunity:
– Overvoltage protected ACS switches:
ACST610-8FP for compressor control,
ACS110-7SN for defrost resistor and
ACS102-6TA for light bulb and fan
– Class A criteria for IEC 61000-4-4 up to
above 3 kV levels
■Flexibility:
– Development: program setting with PC
interface to change firmware variables
– Industrialization: end-of-production MCU
programming thanks to FLASH, for soft
upgrade and efficient MCU stock
management
■RoHS compliant
Description
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
a light bulb, and optionally, a defrost resistor and a
fan, working on 220/240 VRMS, 50/60 Hz mains
voltage. The thermostat kit is operational with
100/120 V RMS 50/60 Hz but the supply capacitor
value must be modified.
The board can operate in an ambient temperature
range from 0 °C to 60 °C.
The exact maximum temperature depends on the
power of the loads. For demonstrative purposes a
graphic user interface (GUI) has been developed.
The connection between the PC and STM8S
microcontroller, the MCU performing thermostat
regulation, is achieved through a USB bus.
As the STM8S is a low-cost MCU without an
embedded USB peripheral, an additional MCU
(STM32) has been used as a bridge between the
PC and STM8S MCU, for demonstrative purposes
only.
www.st.com
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Doc ID 023175 Rev 3 5/7
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STEVAL-IHT001V2
Doc ID 023175 Rev 3 7/7
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