초록 ▼

To provide a vehicular air conditioning system for activating an electric heater with the output coming from an inverter by actuating a relay at a reasonable cost, a relay and an electric heater acting as electric heat source are connected in series between an output line of three output lines of an

To provide a vehicular air conditioning system for activating an electric heater with the output coming from an inverter by actuating a relay at a reasonable cost, a relay and an electric heater acting as electric heat source are connected in series between an output line of three output lines of an inverter and the negative side of a vehicular power supply. The electric heater employs a nichrome wire as its heating element and is used for warming the inside of a vehicle compartment. Moreover, the relay is turned ON/OFF after the output voltage of the inverter is set to zero. As a result, the durability of the relay can be improved, and this relay can be implemented by an existing one without newly manufacturing any dedicated relay so that the cost can be lowered.

대표청구항 ▼

[ What is claimed is:] [1.] A vehicular air conditioning system comprising:an air conditioning compressor driven by an AC motor of three or more phases;an inverter for converting an output of a vehicular power supply into AC power to control the AC motor, the inverter having three or more output lin

[ What is claimed is:] [1.] A vehicular air conditioning system comprising:an air conditioning compressor driven by an AC motor of three or more phases;an inverter for converting an output of a vehicular power supply into AC power to control the AC motor, the inverter having three or more output lines for supplying the AC power to each phase of the AC motor;an electrical heating unit connected to one of the output lines of the inverter so that vehicular power is supplied to the electrical heating unit through the one of the output lines of the inverter;a switching unit for switching power from the one of the output lines of the inverter to the electrical heating unit;signal generating means for generating an instruction signal to turn on the switching unit; andcontrol means for reducing an output voltage of the invertor in response to the instruction signal prior to actuating the switching unit to switch the power to the electrical heating unit.