JPH08223794A - Power device having battery - Google Patents

Abstract

PURPOSE: To prevent the malfunctioning of a control apparatus having a battery as a power source at the time of battery exchange, by discharging a capacitor at the time of battery removal by a discharging circuit, and lowering the discharge voltage of the capacitor in a short time after the battery is removed. CONSTITUTION: A discharging part 9 having a ground short-circuiting circuit for causing the discharge of a capacitor 8 to flow to the ground like a short circuit at the time of the removal of a battery 1 is provided. If the battery 1 is removed, input voltage to a voltage monitoring part 7 lowers. When this input voltage becomes lower than a specified voltage, the ground short-circuiting circuit of the discharging part 9 is operated and closed, and the positive terminal of the capacitor 8 is short-circuited to the ground. Consequently, the discharge voltage of the capacitor 8 lowers rapidly. As a result, it becomes possible to prevent imperfect voltage from being applied to a control part 6, etc., for a long time, and to prevent the malfunctioning of a control apparatus having a battery 1 as a power source at the time of the exchange of batteries 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device having a battery.

[0002]

2. Description of the Related Art In a device using a battery as a power source, a battery removal detecting device is used which detects a battery replacement and outputs a reset signal to a CPU of a control circuit, as disclosed in JP-A-6-49883.

FIG. 2 is a block diagram showing a control circuit configuration of an automatic water faucet using a battery as a power source. The voltage and current from the battery 1 are a stabilizing unit (stabilized power supply circuit) 2, a driving unit (solenoid drive). It is supplied to the circuit 3 and the load (solenoid) 4. A predetermined voltage is supplied from the stabilization unit 2 to the sensor unit (sensor for detecting a hand) 5 and the control unit 6,
A drive signal is supplied from the control unit 6 to the drive unit 3, and an operation signal is output from the drive unit 3 to the load 4.

The voltage of the battery 1 is monitored by the voltage monitoring unit 7, and when the battery is removed for replacement, the voltage monitoring unit 7
Is output to the control unit 6. Upon receiving this signal, the control unit 6 controls the automatic faucet so as to keep the water discharge stopped.

A capacitor 8 provided in parallel with the battery 1.
Is installed so that a sufficient current flows through the load 4 when the load (solenoid) 4 is turned on. A first diode 11 is provided to prevent backflow of current from the capacitor 8 to the voltage monitoring unit 7 after the battery 1 is removed.

[0006]

In the control circuit shown in FIG. 2, even if the battery 1 is removed, the control section 6 and the like can be put into operation by the charge stored in the capacitor 8. Since the discharge voltage of No. 2 gradually decreases, the control unit 6 and the like are operated at a halfway voltage lower than the specified voltage, which may cause the entire device to malfunction.

Further, in a device using a battery as a power source, when the battery capacity is lowered, a mode (hereinafter, referred to as a dead battery mode) in which all the operations other than displaying the battery capacity decrease by an LED or the like are stopped There is. This dead battery mode must be canceled when the battery is replaced with a new one, and normal operation must be restored. However, if the battery is replaced before the discharge voltage from the capacitor 8 is sufficiently lowered, the control unit does not return to the initial state, so the dead battery mode is not released, and the battery may be replaced with a new one. However, it may not operate normally.

An object of the present invention is to provide a power supply device having a battery that can reduce the discharge voltage of the capacitor within a short time after the battery is removed.

[0009]

According to a first aspect of the present invention, there is provided a power supply device having a battery, the power supply device comprising a battery and a capacitor for stabilizing the power supply voltage provided in parallel with the battery. It is characterized in that a discharge circuit for discharging the charge is provided.

According to a second aspect of the present invention, there is provided a power supply device having a battery according to the first aspect, wherein a diode is provided between the battery and the capacitor such that a direction toward the capacitor is a forward flow direction, and a reverse current from the diode is provided. Is provided to the ground, and the discharging circuit performs the discharging when the voltage on the battery side of the diode becomes lower than a predetermined voltage.

[0011]

When the battery is removed, the charge of the capacitor is discharged by the discharge circuit, so that the discharge voltage of the capacitor drops rapidly.

In the second aspect, the reverse current of the diode is released to the ground by the bypass circuit, so that the input voltage to the voltage monitoring unit when the battery is removed can be quickly reduced.

[0013]

FIG. 1 is a circuit block diagram of an automatic water faucet equipped with a power supply device having a battery according to an embodiment of the present invention. A grounding short circuit for discharging the capacitor 8 to the ground when the battery 1 is removed is shown. A discharge unit 9 having the same is provided.

The voltage monitoring unit 7 closes the earth short circuit of the discharging unit 9 when the terminal voltage of the diode 11 on the battery side becomes lower than a predetermined voltage.

In this embodiment, a bypass circuit 14 for releasing the reverse current from the first diode 11 to the ground is provided, and the bypass circuit 14 is provided.
In addition, the second diode 12 is provided so that the reverse flow direction is the ground direction, and the third diode 13 is further installed with the forward flow direction being the ground direction. The same diode as the first diode 11 is used as the second diode 12. The other configuration of FIG. 1 is the same as that of FIG. 2, and the same reference numerals indicate the same parts.

In the device of this embodiment, when the battery 1 is removed, the input voltage to the voltage monitoring unit 7 drops, and when the input voltage becomes lower than the predetermined voltage, the earth short circuit of the discharging unit 9 closes. , The positive terminal of the capacitor 8 is shorted to ground. This causes the discharge voltage of the capacitor 8 to drop rapidly. As a result, it is possible to prevent the halfway voltage from being applied to the control unit 6 and the like for a long period of time, and prevent the automatic faucet from malfunctioning.

In particular, in the apparatus of this embodiment, the provision of the bypass circuit 14 allows the reverse current from the first diode 11 to flow to the ground when the battery is removed, so that the voltage monitoring unit 7 can be operated. Input voltage drops rapidly. As a result, removal of the battery 1 can be quickly detected. The second diode 12
Prevents the current from the battery 1 from being shorted to ground.

In the device of this embodiment, since the third capacitor 13 is provided, it is possible to prevent the current from flowing in the bypass circuit 14 in a short circuit even if the battery 1 is installed in the +-and -opposite directions. To be done.

[0019]

In the device of the present invention, the discharging section discharges the electric charge of the capacitor for stabilizing the power supply voltage, thereby speeding the decrease of the power supply voltage of the control section. As a result, the power supply voltage to the control unit is quickly reduced to a voltage at which the control unit is in the initial state, and it is possible to prevent malfunction of the control device using the battery as a power source when the battery is replaced.

According to the second aspect of the present invention, since the bypass circuit for flowing the reverse current of the diode to the ground side is provided, the delay of the voltage drop due to the influence of the reverse current is eliminated,
It is possible to reliably prevent malfunction of the control device when the battery is replaced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a device according to an embodiment.

FIG. 2 is a block diagram showing a circuit configuration of a conventional device.

[Explanation of symbols]

 1 Battery 6 Control Section 7 Voltage Monitoring Section 8 Capacitor 9 Discharging Section 11, 12, 13 Diode 14 Bypass Circuit

Claims (2)

[Claims] 1. A power supply device comprising a battery and a capacitor for stabilizing the power supply voltage provided in parallel with the battery, wherein a discharge circuit for discharging the charge of the capacitor when the battery is removed is provided. Power supply device having a battery. 2. The diode according to claim 1, wherein a diode is provided between the battery and the capacitor so that a direction toward the capacitor is a forward flow direction, and a bypass circuit for flowing a reverse current from the diode to the ground is provided. A power supply device having a battery, wherein the discharge circuit discharges when the voltage of the diode on the battery side becomes lower than a predetermined voltage.