Fluid temperature control using heat exchanger

The paper presents an automated system used for the temperature control of the fluid, using a heat exchanger heated by an electrical resistance. The fluid is re-circulated through the exchanger by a d.c. electro-pump. The control algorithm is an on-off type with hysteresis one and it is implemented with a PIC microcontroller and a relay as its actuator. The most important data is presented on a seven segments display. In order to send the parameters of the process and the command states to the computer, the serial communication is used.