초록 ▼

When a lock detector detects a locked state of a DC motor in a starting stage, a torque increasing circuit immediately selects a starting sequence pattern of an output torque that is greater in magnitude by one preselected step, and outputs the selected output torque to a starting sequence controlle

When a lock detector detects a locked state of a DC motor in a starting stage, a torque increasing circuit immediately selects a starting sequence pattern of an output torque that is greater in magnitude by one preselected step, and outputs the selected output torque to a starting sequence controller, so that a compressor can be restarted speedily without repeating starting failures. A compressor, driven by a DC motor, has a shell of an internal pressure approximately equal to the pressure of an inhalation gas. An inverter is provided to make the speed of the DC motor variable. A rotational frequency setting circuit sets the rotational frequency of the DC motor to a frequency that is not greater than the frequency of a commercial power source when the internal temperature of a refrigerator is stabilized. By this construction, the power consumption can be remarkably reduced.

대표청구항 ▼

[ We claim:] [1.] A control device for use with a refrigerator having an internal temperature, and a commercial power source having a commercial power frequency, and for controlling a low-pressure shell compressor of the refrigerator which includes a shell having an internal pressure approximately e

[ We claim:] [1.] A control device for use with a refrigerator having an internal temperature, and a commercial power source having a commercial power frequency, and for controlling a low-pressure shell compressor of the refrigerator which includes a shell having an internal pressure approximately equal to a pressure of an inhalation gas during operation, a compressing section accommodated in the shell, and a DC motor for operating the compressing section and having a rotor and a stator, which includes stator windings operable to output a reverse induction voltage, said control device comprising:a reverse induction voltage detector circuit, electrically connectable to the stator windings, for detecting a rotational position of the rotor from the reverse induction voltage output by the stator windings and for producing an output signal indicative of the rotational position of the rotor;a rotational frequency setting circuit for setting a desired rotational frequency of the DC motor to be lower than the commercial power frequency when the internal temperature of the refrigerator is stabilized and for producing an output indicative of the desired rotational frequency;an inverter, electrically connectable to the DC motor, for executing a commutating operation based on the output of said reverse induction voltage detector circuit during normal operation so as to operate the DC motor at a variable speed and for producing an output voltage according to the commutating operation.