Abstract: With the rapid development of sensors of temperature and microchips in these years, the intelligent switch based on the two technologies has more flexibility and a wide application range.
This paper introduces a circuit of temperature measurement based on MCS-51 chip microcomputer. The system uses AD590 as temperature sensor, ADC0804 as Mod-Digit switcher, correct error, judge sensor failure and give over-temperature alarm. It also has the functions of panel controlling and alarm communication and displaying.
Main features of this switch: The working range of the switch is from -50℃~+125℃ degrees; The switch will be put into work at the zero crossover of the voltage without arc or mechanical noise;, the system is more flexible and has a wide application ranges; The value of the temperature can be modified by the user; The switch will produce no EMI to the environment.
This switch is designed for the temperature control of the Intelligent Building, the factory who has special limitations to temperature.