Power supply system and power supply method

A power supply system for a vehicle including a load, the power supply system comprising:

• a first power supply having a first supply voltage;
• a second power supply having a second supply voltage larger than the first supply voltage;
• a semiconductor switch drivable with the second supply voltage and connected between the first power supply and the load;
• and
• a drive circuit using the second supply voltage to produce an on-off drive signal to drive the semiconductor switch, wherein
• the load comprises a tail lamp of the vehicle, and
• the second power supply comprises a battery installed in a front part of the vehicle.

A power supply system for a vehicle including a motor having first and second electrodes different of polarity, and grounding circuitry, the power supply system comprising:

• a first power supply having a first supply voltage;
• a second power supply having a second supply voltage larger than the first supply voltage;
• a first semiconductor switch connected between the first power supply and the first electrode of the motor;
• a second semiconductor switch connected between the first power supply and the second electrode of the motor;
• a third semiconductor switch drivable with the second supply voltage and connected between the second electrode of the motor and the grounding circuitry;
• a fourth semiconductor switch drivable with the second supply voltage and connected between the first electrode of the motor and the grounding circuitry;
• a first drive circuit configured to drive the first semiconductor switch;
• a second drive circuit configured to drive the second semiconductor switch;
• a third drive circuit using the second supply voltage as a drive signal to drive the third semiconductor switch;
• a fourth drive circuit using the second supply voltage as a drive signal to drive the fourth semiconductor switch;
• and
• a controller configured to synchronously control the first, second, third and fourth drive circuits to control a rotating direction of the motor.

A power supply system in which on/off control of a semiconductor switch is performed to control supply of electrical power from a first power supply to a load, comprising:

• a second power supply with a second voltage larger than a first voltage of the first power supply;
• and
• a driver outputting to a control input terminal of the semiconductor switch an on/off control signal for performing on/off control of the semiconductor switch, wherein the driver uses the second voltage supplied from the second power supply to produce the on/off control signal, wherein
• the second power supply comprises a battery installed in a front part of a vehicle.

A power supply system comprising:

• a first semiconductor switch connected to a first power supply and to a first end of a motor;
• a second semiconductor switch connected to a second end of the motor and to ground;
• a third semiconductor switch connected to the first power supply and to the second end of the motor;
• a fourth semiconductor switch connected to the first end of the motor and to ground;
• a second power supply having a second voltage, larger than a first voltage of the first power supply and capable of on/off controlling the first and third semiconductor switches;
• a first driver outputting to a control input terminal of the first semiconductor switch a signal for performing on/off control of the first semiconductor switch by means of the second voltage;
• a second driver performing on/off control of the second semiconductor switch linked to on/off control of the first semiconductor switch;
• a third driver outputting to a control input terminal of the third semiconductor switch a signal for performing on/off control of the third semiconductor switch by means of the second voltage;
• and
• a fourth driver performing on/off control of the fourth semiconductor switch linked to on/off control of the third semiconductor switch.

A power supply method comprising:

• providing a first power supply having a first supply voltage;
• providing a second supply voltage larger than the first supply voltage;
• connecting an n-channel field-effect transistor between the first power supply and a load, as a semiconductor switch drivable with the second supply voltage, having
• a drain thereof connected to the first power supply,
• a source thereof connected to the load, and
• a gate thereof connected to the drive circuit;
• and
• generating a drive signal to drive the semiconductor switch using the second supply voltage.

A power supply method for a vehicle including a tail lamp as a load, the power supply method comprising:

• providing a first power supply having a first supply voltage;
• providing a battery in a front part of the vehicle, as a second power supply having a second supply voltage larger than the first supply voltage;
• connecting a semiconductor switch between the first power supply and the load, the semiconductor switch being drivable with the second supply voltage;
• and
• generating a drive signal to drive the semiconductor switch using the second supply voltage.

A method for supplying electrical power from a first power supply to a load by performing on/off control of a semiconductor switch, the method comprising:

• supplying to a driver from a second power supply a second voltage larger than a first voltage from the first power supply and capable of on/off controlling the semiconductor switch;
• and
• outputting to a control input terminal of the semiconductor switch an on/off control signal for on/off controlling the semiconductor switch, the on/off control signal being produced using the second voltage supplied to the driver from the second power supply, wherein
• the second power supply comprises a battery installed in a front part of a vehicle.

A power supply system comprising:

• a first power supply outputting a first supply voltage to operate a low-voltage load;
• a second power supply outputting a second supply voltage greater than the first supply voltage, to operate a high-voltage load;
• a semiconductor switch connected between the first power supply and the low-voltage load;
• and
• a drive circuit configured to drive the semiconductor switch, wherein
• the semiconductor switch comprises a field-effect transistor having a drain thereof connected to the first power supply, and a source thereof connected to the low-voltage load, the field-effect transistor being drivable with the second supply voltage, and
• the drive circuit comprises
• a switching circuit connected to the second power supply,
• an output resistor connected between the switching circuit and a gate of the field-effect transistor, and
• a Zener diode connected between the output resistor and the source of the field-effect transistor.

A power supply system for vehicles including a low-voltage load and a high-voltage load, the power supply system comprising:

• a first power supply outputting a first supply voltage to operate the low-voltage load;
• a second power supply outputting a second supply voltage greater than the first supply voltage, to operate the high-voltage load;
• a semiconductor switch connected between the first power supply and the low-voltage load;
• and
• a drive circuit configured to drive the semiconductor switch, wherein
• the semiconductor switch comprises a field-effect transistor having a drain thereof connected to the first power supply, and a source thereof connected to the low-voltage load, the field-effect transistor being drivable with the second supply voltage;
• and
• the drive circuit comprises
• a switching circuit connected to the second power supply,
• an output resistor connected between the switching circuit and a gate of the field-effect transistor, and
• a Zener diode connected between the output resistor and the source of the field-effect transistor.

A power supply system for vehicles including a low-voltage load provided with a motor having a first and a second electrode mutually different in polarity, a high-voltage load, and grounded circuitry, the power supply system comprising:

• a first power supply outputting a first supply voltage to operate the low-voltage load;
• a second power supply outputting a second supply voltage greater than the first supply voltage, to operate the high-voltage load;
• a first semiconductor switch connected between the first electrode of the motor and the grounded circuitry;
• a second semiconductor switch connected between the second electrode of the motor and the grounded circuitry;
• a third semiconductor switch connected between the first power supply and the first electrode of the motor;
• a fourth semiconductor switch connected between the first power supply and the second electrode of the motor;
• a first drive circuit configured to drive the first semiconductor switch;
• a second drive circuit configured to drive the second semiconductor switch;
• a third drive circuit configured to drive the third semiconductor switch;
• a fourth drive circuit configured to drive the fourth semiconductor switch;
• and
• a controller configured for synchronous control of the first, the second, the third, and the fourth drive circuit to control a rotational direction of the motor, wherein
• one of the first and the second semiconductor switch comprises a first n-channel field-effect transistor having a drain thereof connected to the first power supply, and a source thereof connected to one of the first and the second electrode of the motor, the first n-channel field-effect transistor being drivable with the second supply voltage, and
• one of the first and the second drive circuit comprises
• a first switching circuit connected to the second power supply,
• a first output resistor connected between the first switching circuit and a gate of the first n-channel field-effect transistor, and
• a first Zener diode connected between the first output resistor and the source of the first n-channel field-effect transistor.

A power supply system for vehicles including:

• a first power supply line supplying power of a low voltage to a low-voltage load;
• a second power supply line supplying power of a high voltage to a high-voltage load;
• a semiconductor switch installed in the first power supply line;
• and
• a drive circuit configured to drive the semiconductor switch, wherein
• the semiconductor switch comprises a field-effect transistor having a drain thereof connected to the first power supply line, and a source thereof connected to the low-voltage load, the field-effect transistor being drivable with the high voltage, and
• the drive circuit comprises
• a switching circuit connected to the second power supply line,
• an output resistor connected between the switching circuit and a gate of the field-effect transistor, and
• a Zener diode connected between the output resistor and the source of the field-effect transistor.

A power supply method including:

• providing a first voltage to operate a low-voltage load;
• supplying the first voltage to the low-voltage load through a semiconductor switch;
• and
• on-off controlling the semiconductor switch, wherein the power supply method comprises:
• having the semiconductor switch configured with a field-effect transistor drivable with a second voltage greater than the first voltage;
• connecting a source of the field-effect transistor to the low-voltage load;
• supplying the first voltage to a drain of the field-effect transistor;
• supplying the second voltage to a gate of the field-effect transistor through a switching circuit and an output resistor;
• connecting a Zener diode between the output resistor and the source of the field-effect transistor;
• and
• on-off controlling the switching circuit.

A power supply method for vehicles including a low-voltage load and a high-voltage load, the power supply method comprising:

• providing a first voltage to operate the low-voltage load;
• providing a second voltage greater than the first voltage, to operate the high-voltage load;
• providing a field-effect transistor on-off drivable with the second voltage;
• connecting a source of the field-effect transistor to the low-voltage load;
• supplying the first voltage to a drain of the field-effect transistor;
• supplying the second voltage to a gate of the field-effect transistor through a switching circuit and an output resistor;
• connecting a Zener diode between the output resistor and the source of the field-effect transistor;
• and
• on-off controlling the switching circuit.