JPH09233717A - Power control device - Google Patents

Abstract

(57) Abstract: In a device using a primary battery and a secondary battery in parallel, the consumption of the battery due to the current flowing from the primary battery to the secondary battery due to the voltage difference is reduced. SOLUTION: The positive terminal of the dry battery 1 is connected to the resistors R1 and FE.
It is connected to the positive terminal of the rechargeable battery 2 via a parallel circuit with TQ1. The mechanism control microcomputer 6 is activated, and the transistor Q2 is connected through the resistor R5.
Is turned on and the first booster circuit 4 operates, whereby the main microcomputer 7 is activated and enters the standby state. When the key input S1 to S4 of the device is pressed, the data is sent from the main microcomputer 7 to the mechanism controlling microcomputer 6 and the mechanism driving output is output from the mechanism controlling microcomputer 6, which turns on the transistor Q6. Then, the output of the voltage doubler block 3 turns on the FET Q1 to short-circuit the resistor R1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device for portable electronic equipment such as headphone stereos, and more particularly to equipment capable of simultaneously supplying a primary battery and a secondary battery in parallel as a driving power supply. The present invention relates to a power supply control device for reducing consumption of a primary battery.

[0002]

2. Description of the Related Art In recent years, in headphone stereos and the like,
As a result of efforts to reduce the current consumption of the mechanism and the current consumption of the ICs forming the electric circuit, the current consumption of the device has been remarkably reduced. However, continuous use for a longer period of time has been required, and for this reason, by installing an additional dry battery in parallel from the outside to a device that has a built-in secondary battery such as a nickel-hydrogen rechargeable battery, the total electric capacity can be increased. Is used to enable long-term operation.

[0003]

However, in the conventional device having such a structure, when the dry battery, which is the primary battery, is new, the current from the dry battery to the rechargeable battery, which is the secondary battery, is changed due to the potential difference between the dry battery and the secondary battery. Current flows in, but when the rechargeable battery is fully charged, the current that flows in is lost. This current always flows even when the device is not used, and there is a problem that it continues to flow until the voltage of the dry battery becomes equal to the voltage of the rechargeable battery, and the current consumption of the mechanism and the electric circuit has been significantly reduced, The influence of such losses is increasing.

In order to solve the above-mentioned conventional problems, the present invention has been made for the purpose of providing a power supply control device for reducing a current flowing into a rechargeable battery when the device is not used, that is, in a standby state. It is a thing.

[0005]

In order to solve the above problems, a power supply control device of the present invention has a primary battery having first and second terminals, and first and second terminals.
A terminal of the secondary battery connected to the second terminal of the primary battery, a first terminal of the primary battery and a first terminal of the secondary battery.
A resistor connected between the resistor and a terminal, a short-circuiting device connected in parallel with the resistor and being in an open state when the device is not operating, and short-circuiting the short-circuiting device when detecting that the device is in an operating state. And a control means for controlling as described above.

According to the present invention, since the short-circuit means is in the open state when the device is in the standby state, the current flowing from the primary battery to the secondary battery due to the voltage difference between the primary battery and the secondary battery is a resistor. It is possible to provide a power supply control device that is limited by the above and can reduce battery consumption.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention has a primary battery having first and second terminals, and first and second terminals, the second terminal being the primary battery. A secondary battery connected to the second terminal of the battery, a resistor connected between the first terminal of the primary battery and the first terminal of the secondary battery, and connected in parallel to the resistor And a control means for controlling the short-circuiting means to be short-circuited when detecting that the equipment is in an operating state. When is in the standby state, the short-circuit means is in the released state, so the current flowing from the primary battery to the secondary battery is limited by the resistor due to the voltage difference between the primary battery and the secondary battery,
Acts to reduce battery consumption.

According to a second aspect of the present invention, in the structure of the first aspect, the short-circuit means is a field effect transistor, and the gate of the field-effect transistor is controlled by the control means so as to short-circuit the field effect transistor. The configuration further includes a boosting means for applying a voltage that can be turned on. With this configuration, the field effect transistor can be surely turned on when the device is operating, and the action of claim 1 can be surely achieved.

According to a third aspect of the present invention, the voltage of the secondary battery is directly used as a power supply voltage, the voltage of the primary battery is connected in parallel to the secondary battery via a resistor, and the resistor is connected. A field effect transistor is connected in parallel to the first booster circuit when the electric circuit and the mechanism are in a standby state to operate the first booster circuit so that the control means is operable. To operate the second step-up circuit and stop the operation of the first step-up circuit when the radio receiving circuit is in operation so that the control means can operate with the output of the second step-up circuit, A power supply control device characterized by turning on the field effect transistor when any of the circuit and the mechanism and the radio receiving circuit operates, Because the field effect transistor is in the open state when the device is in the standby state, the current flowing from the primary battery to the secondary battery is limited by the resistor due to the voltage difference between the primary battery and the secondary battery. It acts to reduce wear and
During operation of the radio receiving circuit, the first booster circuit is stopped to use the second booster circuit in order to avoid the influence of noise generated during boosting, and the second boosted voltage is applied to the gate of the field effect transistor. This turns on the resistor and short-circuits the resistor in series with the dry battery to supply the current necessary for the operation of the device.

Embodiments of a power supply control device of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a power supply control device according to an embodiment of the present invention, showing a case where the power supply control device is used for a headphone stereo with a tuner.

In FIG. 1, a positive terminal of a dry battery 1 which is a primary battery having an internal resistance r1 is connected to a positive terminal of a rechargeable battery 2 which is a secondary battery via a resistor R1. As a rechargeable battery, a nickel-hydrogen battery is used here as an example, and this internal resistance is neglected because it is much lower than that of the dry battery 1. The negative terminals of the dry battery 1 and the rechargeable battery 2 are both grounded. A field effect transistor (hereinafter referred to as FE) as a short-circuit means is connected in parallel with the resistor R1.
T) Q1 has a drain connected to the dry battery 1 side and a source connected to the rechargeable battery 2 side. Then, the power supply voltage is directly supplied from the positive terminal side of the rechargeable battery 2 to each circuit block and mechanism (not shown).

The voltage doubler rectifier circuit block 3 has the number of stages necessary for boosting the oscillation waveform output of the first booster circuit 4 until a voltage that can sufficiently turn on the FET of Q1 is obtained. The first booster circuit 4 is intended for low current consumption and is mainly operated when the tape is driven, and mainly supplies power to the main microcomputer 7 and voltage to a photo LED (not shown) for detecting tape rotation. It is intended for use. The second booster circuit 5 is intended for low noise, is mainly operated in the tuner receiving state, and is provided with a voltage line for driving the varicap to the electronic tuning circuit block 8. In the operating state of the second booster circuit 5, the first booster circuit 4 is controlled to stop. The mechanism control microcomputer 6 is a microcomputer that controls a mechanism (not shown) and also controls the activation of the first booster circuit 4. Main microcomputer 7
Detects a key input from a tape key, a radio key, or the like provided on the device or a key input from the remote control microcomputer 9, and responds to the input by the mechanism control microcomputer 6 or the remote control microcomputer 9
Send data to and give a command.

Further, S1 to S5 are key input buttons provided in the equipment, for example, S1 is a PLAY key and S2.
Is the STOP key. Although S3 is an FF key, it has a role of fast-forwarding during tape operation, and memory up and frequency up in tuner reception mode. Although S4 is a REW key, it rewinds when the tape is operating, and has a role of memory down and frequency down in the tuner reception mode. Further, S5 is a radio key, which has a role of turning on the radio operation during stop or tape operation. Q2 to Q5 are transistors, D1 is a diode, and R1 to R5 are resistors.

The circuit operation configured as described above will be described below. First, when only the rechargeable battery 2 is attached, the terminal voltage V _cc2 of the rechargeable battery ₂ is directly supplied as a drive power source for the device, and first, the mechanism controlling microcomputer 6 is operated and the resistor R5 is used to
The transistor Q2 is turned on, the power supply voltage V _cc2 is applied to the control terminal of the first booster circuit 4 connected to the collector of the transistor Q2, the first booster circuit 4 enters the operation mode, and the boosted output voltage V _DD1 is _supplied . Output. When the V _DD1 is output, the main microcomputer 7 is activated and enters the so-called standby state, and the key input S1 to S5 of the device and the data from the remote control microcomputer 9 cause the standby mode to shift to the operation mode corresponding to the input. . For example, when the PLAY button S1 is pressed, data is sent from the main microcomputer 7 to the mechanism controlling microcomputer 6 and an output for driving the mechanism is output from the mechanism controlling microcomputer 6. At the same time, the transistor Q6 is turned on by the mechanism control microcomputer 6 to turn on the voltage doubler rectifier circuit block 3
Is applied to the gate of the FET Q1 to turn on the FET Q1, but since the dry battery 1 is not connected, it is not related to the operation.

When the radio key S5 is pressed, the main microcomputer 7 issues a command to turn on the transistor Q5 through the resistor R3. When the transistor Q5 is turned on, the transistor Q4 is turned on through the resistor R4 and the second booster circuit 5 is _supplied with the power supply voltage _Vcc2.
Is supplied, and the second booster circuit 5 operates. In this case, when the transistor Q5 is turned on, the transistor Q3 is turned on, and as a result, the base of the transistor Q2 becomes the V _CC2 potential, the transistor Q2 is turned off, and the first booster circuit 4 is stopped. When the second booster circuit 5 operates, the driving voltage V _DD1 is applied to the main microcomputer 7 and the varicap driving voltage V _{DD2 (} not shown) is applied to the electronic tuning circuit block 8 constituting the tuner. At this time, voltage V _DD2 is diode D
1 is also applied to the gate of FETQ1
1 is turned on, but it is not related to the operation because the dry battery 1 is not attached.

Next, a case where only the dry battery 1 is mounted will be described. When the dry battery 1 is installed without the rechargeable battery 2 being installed, the voltage V _{CC1 of the} dry battery 1 is applied to the resistor R1 through the internal resistance r1. The circuit operation after the voltage V _CC1 is applied is the same as that when the rechargeable battery 2 is attached, but there is no key input in the standby state, so that there is no instruction from the mechanism controlling microcomputer 6, The transistor Q6 is off and the FET of Q1 is also off. S1
In the tape operating state after the key input of S4 to S4, the transistor Q6 is turned on by the instruction of the mechanism controlling microcomputer 6 by the key input, thereby turning on the FET Q1 and short-circuiting both ends of the resistor R1. A FET having a low ON resistance is used for the FET Q1 so that a current required for the mechanism operation can be supplied. Regarding the radio operation after the input of the radio key S5, as described above, the first booster circuit 4 in which noise easily jumps into the tuner reception band is stopped and the second booster circuit 5 is activated to operate the varicap application voltage line V _DD2. Is applied to the gate of the FET Q1 through the diode D1 and the FET Q1 is turned on. In addition, when the first booster circuit 4 is activated, the resistor R1
Since the voltage V _CC2 instantaneously decreases due to the current flowing in the resistor R1, it is necessary to select the resistor R1 so that the first booster circuit 4 operates even in this state. Start current I _st of the booster circuit, the internal resistance r1 of the battery, when the open-circuit voltage of the battery and _{V CC1 V CC1 -I st (r1} + R1) = V CC2 , and the decrease of the voltage V _CC2 first booster circuit 4 Making R1 as large as possible within the startable range of 1 reduces the loss when the dry battery and the rechargeable battery are used together. The standby current after the booster circuit is started is generally several tens to several hundreds μ.
Since it is A, the value of the resistor R1 is determined by the starting condition of the circuit because it is extremely smaller than the starting current.

Next, a case where a rechargeable battery and a dry battery are used together will be described. The circuit state after key input is the same as the above description, and during mechanism operation or radio operation,
FET Q1 is on. In the standby state, FE
TQ1 is off and is supplying circuit current through resistor R1. When the dry battery 1 is new, the voltage V
_CC1 is at a potential higher than the voltage V _CC2 , a current flows into the rechargeable battery 2, and the inflow current I _Batt2 becomes I _Batt2 = (V _CC1 −V _CC2 ) / (r1 + R1). Conventionally, an inflow current depending on the internal resistance r1 of the dry battery is generated because the resistor R1 is not provided. For example, assuming that the internal resistance r1 of the dry battery is _0.5Ω , if the resistor R1 is _10Ω , then I _Batt2 Can be reduced to about 1/20.

In the above description, the first booster circuit 4 and the second booster circuit 4
It has been described that the first booster circuit 4 is stopped when the second booster circuit 5 operates by using the booster circuit 5 of FIG. Although it was possible to stop the tape mechanism during operation, it is necessary to use a second booster circuit with less noise for radio recordable equipment.

Although the nickel-metal hydride battery is used as an example of the rechargeable battery in the present embodiment, the rechargeable battery may be a nickel-cadmium battery, a lithium-ion battery, a lead storage battery, or the like. As the dry battery, an alkaline dry battery or the like can be used in addition to the normal manganese dry battery. Although the headphone stereo with a tuner has been described, the corresponding circuit may be omitted for those without a tuner.

Further, a means for short-circuiting the resistor R1 is FET
Although it is performed in Q1, it is obvious that it can be realized by a mechanical switch or a relay contact linked to the operation of the mechanism.

[0021]

As described above, the power supply control device of the present invention has the primary battery having the first and second terminals and the first and second terminals, and the second terminal is the primary battery. A secondary battery connected to the second terminal, a resistor connected between the first terminal of the primary battery and the first terminal of the secondary battery, and a resistor connected in parallel to the resistor. When the device is in the standby state by the configuration including the short-circuiting device which is in the released state when the device is not operating, and the control device which controls to short-circuit the short-circuiting device when detecting that the device is in the operating state, Since the short-circuit means is in the released state, the current flowing from the primary battery to the secondary battery due to the voltage difference between the primary battery and the secondary battery is limited by the resistor, and a power control device capable of reducing battery consumption is provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a power supply control device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Dry Battery (Primary Battery) 2 Rechargeable Battery (Secondary Battery) 3 Double Voltage Rectifier Circuit Block 4 First Booster Circuit 5 Second Booster Circuit 6 Mechanism Control Microcomputer 7 Main Microcomputer 8 Electronic Tuning Circuit Block 9 Remote Control Microcomputer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H02J 9/06 503 H02J 9/06 503E

Claims (3)

[Claims] 1. A primary battery having first and second terminals, a secondary battery having first and second terminals, the second terminal being connected to the second terminal of the primary battery. A resistor connected between the first terminal of the primary battery and the first terminal of the secondary battery; and a short-circuit means connected in parallel to the resistor and being in an open state when the device is not operating, A power supply control device comprising: a control unit that controls to short-circuit the short-circuiting unit when detecting that the device is in an operating state. 2. The short-circuit means is a field effect transistor, and further comprises booster means for applying a voltage capable of turning on the gate of the field-effect transistor when controlled by the control means to short-circuit. The power supply control device described. 3. The voltage of the secondary battery is directly used as a power supply voltage, the voltage of the primary battery is connected in parallel to the secondary battery via a resistor, and the field effect transistor is connected in parallel to the resistor. In the standby state of the electric circuit and the mechanism, the first booster circuit is operated so that the control means is operable, the first booster circuit is operated during the operation of the mechanism and the reproduction circuit, and during the operation of the radio receiving circuit. Any one of the reproducing circuit, the mechanism, and the radio receiving circuit is operated by operating the second boosting circuit and stopping the operation of the first boosting circuit so that the control means can operate with the output of the second boosting circuit. Is turned on, the field effect transistor is turned on.