Digital control of integrated circuit temperature using thermoelectric cells and the 8031 microcontroller

A benchtop instrument designed to control the temperature of ICs in the temperature range of -55 degrees C to +125 degrees C for the purpose of testing the ICs, has been developed. During the design phase a number of practical and theoretical control problems were addressed and these are discussed. A computer simulation of the plant dynamics was developed and this simulation has been used to investigate the performance of several PID algorithms, an automatic PID tuner and some self-tuning control strategies. Results of these investigations are presented. The paper then describes the techniques used to resolve problems of actuator nonlinearity, measurement noise, integral saturation and analogue-to-digital converter cost. The effect of reducing digital to analogue converter resolution is also considered.<
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