Automatic temperature control device

An automatic temperature control device comprising series-connected components including a temperature setter (1) of a controlled entity (9), a comparison unit (2) whose second input is connected to an actual temperature transducer (3) of the controlled entity (9), a deviation signal amplifier (4), and a regulating unit (5) furnishing a signal functionally dependent on the deviation signal, the output of said unit being electrically coupled to the input of the actuator (6), and also a unit (8) used to check the circuit of the transducer (3) for continuity, a unit (7) automatically controlling pulse connection of the actuator (6) when the circuit of the transducer (3) is open, said unit being provided with a main electronic switch (12) having its control input connected to the output of the unit (8) used to check the circuit of the transducer (3) for continuity, and operating to apply to the input of the actuator (6) a periodic pulse sequence fed while the circuit of the transducer (3) is open and affecting control to maintain an intermediate temperature in the controlled entity (9) within the operating temperature range, said regulating unit (5) representing a pulse-width modulator comprising a sawtooth voltage generator (36) with a constant pulse-repetition period and a threshold element (37) having its first input connected to the output of the deviation signal amplifier (4) and its second input connected to the output of the sawtooth voltage generator (36), and said threshold element (37) having a regulated operating threshold and includes a respective control input (38) connected to the output of the unit (8) used to check the circuit of the transducer (3) for continuity, while the main electronic switch (12) of the automatic control unit (7) is placed in parallel with the first input of the threshold element (37) of the pulse-width modulator.

An automatic temperature control device comprising series-connected components including a temperature setter (1) of a controlled entity (9), a comparison unit (2) whose second input is connected to an actual temperature transducer (3) of the controlled entity (9), a deviation signal amplifier (4), and a regulating unit (5) furnishing a signal functionally dependent on the deviation signal, the output of said unit being electrically coupled to the input of the actuator (6), and also a unit (8) used to check the circuit of the transducer (3) for continuity, a unit (7) automatically controlling pulse connection of the actuator (6) when the circuit of the transducer (3) is open, said unit being provided with a main electronic switch (12) having its control input connected to the output of the unit (8) used to check the circuit of the transducer (3) for continuity, and operating to apply to the input of the actuator (6) a periodic pulse sequence fed while the circuit of the transducer (3) is open and affecting control to maintain an intermediate temperature in the controlled entity (9) within the operating temperature range, with provision being made for a control action static error compensating unit (39) and the regulating unit (5) representing a pulse-width modulator comprising the sawtooth voltage generator (36) with a constant pulse-repetition period and the threshold element (37) having its first input connected to the output of the deviation signal amplifier (4), its second input connected to the output of the sawtooth voltage generator (36), and the third input thereof coupled to the output of the compensating unit (39) whose input is connected to the output of the setter (1), the main electronic switch (12) of the automatic control unit (7) is placed in parallel with the first input of the threshold element (37) of the pulse-width modulator.