Backup power source device and automobile equipped with same
A backup power source device includes the following elements: a capacitor; a charging circuit provided in the charging path of the capacitor and performing step-down operation; a boost circuit provided in the output path of the capacitor; and a door-lock-releasing output terminal connected to the boost circuit.
1. A backup power source device comprising:
a capacitor;
a charging circuit provided in a charging path of the capacitor and performing step-down operation;
a boost circuit provided in an output path of the capacitor; and
a door-lock-releasing output terminal connected to the boost circuit,
wherein the boost circuit has a switching element and a boost coil disposed on a first side of a substrate, and
the capacitor is disposed on a second side of the substrate opposite to the first side, and series-connected to the switching element and the boost coil.
2. An automobile comprising:
an automobile body;
a door attached to the automobile body and including a door lock and a door-lock-releasing part;
a battery installed in the automobile body;
a backup power source device connected to the battery and disposed in an interior of the automobile body, the backup power source device including:
a capacitor;
a charging circuit provided in a charging path of the capacitor and performing step-down operation;
a boost circuit provided in an output path of the capacitor; and
a door-lock-releasing output terminal connected to the boost circuit;
a vehicle electronic control unit (ECU) for starting the boost circuit of the backup power source device and driving the door-lock-releasing part, using an output of the boost circuit; and
an engine,
wherein the backup power source device further includes a discharging circuit for discharging the capacitor and stopping the discharge in a state where electric charge of the capacitor is left,
in a state where electric power is supplied from the battery to the vehicle ECU, the vehicle ECU starts the discharging circuit depending on a state of whether the engine is started or stopped, and
in a state where no electric power is supplied from the battery to the vehicle ECU, the vehicle ECU starts the boost circuit and drives the door-lock-releasing part, using the output of the boost circuit.
3. An automobile comprising:
an automobile body;
a door attached to the automobile body and including a door lock and a door-lock-releasing part;
a battery installed in the automobile body;
a backup power source device connected to the battery and disposed in an interior of the automobile body, the backup power source device including:
a capacitor;
a charging circuit provided in a charging path of the capacitor and performing step-down operation;
a boost circuit provided in an output path of the capacitor; and
a door-lock-releasing output terminal connected to the boost circuit;
a vehicle electronic control unit (ECU) for starting the boost circuit of the backup power source device and driving the door-lock-releasing part, using an output of the boost circuit;
an ignition switch connected between the battery and a side of an input end of the charging circuit of the backup power source device;
a first diode connected between the input end of the charging circuit and an output end of the boost circuit;
a second diode connected between the vehicle ECU and a node of the battery and the ignition switch; and
a third diode connected between the vehicle ECU and the output end of the boost circuit,
wherein a side of a cathode of the first diode is connected to a side of the output end of the boost circuit, and a side of an anode of the first diode is connected to the input end of the charging circuit,
a side of a cathode of the second diode is connected to the vehicle ECU, and a side of an anode of the second diode is connected to a side of the node of the battery and the ignition switch, and
a side of a cathode of the third diode is connected to the vehicle ECU, and a side of an anode of the third diode is connected to the output end of the boost circuit.
4. The automobile of claim 3 , further comprising:
a first conductor path for connecting the anode and the cathode of the first diode;
a second conductor path for connecting the anode and the cathode of the second diode; and
a third conductor path for connecting the anode and the cathode of the third diode,
wherein a cross-sectional area of the first conductor path and a cross-sectional area of the third conductor path are smaller than a cross-sectional area of the second conductor path.
5. An automobile comprising:
an automobile body;
a door attached to the automobile body and including a door lock and a door-lock-releasing part;
a battery installed in the automobile body;
a backup power source device connected to the battery and disposed in an interior of the automobile body, the backup power source device including:
a capacitor;
a charging circuit provided in a charging path of the capacitor and performing step-down operation;
a boost circuit provided in an output path of the capacitor; and
a door-lock-releasing output terminal connected to the boost circuit;
a vehicle ECU for driving the door-lock-releasing part, using an output of the boost circuit of the backup power source device;
an ignition switch connected between the battery and a side of an input end of the charging circuit of the backup power source device;
a first diode connected between the input end of the charging circuit and an output end of the boost circuit;
a second diode connected between the vehicle ECU and a node of the battery and the ignition switch;
a third diode connected between the vehicle ECU and the output end of the boost circuit;
a control element for starting the boost circuit; and
a voltage divider circuit connected to the output end of the boost circuit,
wherein a side of a cathode of the first diode is connected to a side of the output end of the boost circuit, and a side of an anode of the first diode is connected to the input end of the charging circuit,
a side of a cathode of the second diode is connected to the vehicle ECU, and a side of an anode of the second diode is connected to a side of the node of the battery and the ignition switch,
a side of a cathode of the third diode is connected to the vehicle ECU, and a side of an anode of the third diode is connected to the output end of the boost circuit,
the boost circuit has a smoothing capacitor connected to the output end of the boost circuit, and
the control element starts the boost circuit in response to a voltage dividing signal supplied from the voltage divider circuit or a signal supplied from the vehicle ECU.