JPS61266032A - Power source circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention can be used in television receivers and general electronic equipment, and is used when driving a circuit using a MuC adapter that has a built-in storage battery and is an external DC power source. This invention relates to a power supply circuit that completely stops charging and discharging circuit operations performed via a built-in storage battery.

Conventional technology In recent years, in order to make general electronic equipment such as television receivers smaller, lighter, thinner, and more compact, a combined drive method using an external DC power source and a dry battery or rechargeable storage battery, which is equivalent to an internal power source, has been used. It has been done.

Hereinafter, a conventional example of the above-mentioned power supply circuit will be described with reference to the drawings.

FIG. 2 shows a wiring diagram of a conventional power supply circuit.

Reference numeral 2 denotes an external DC power input socket for connecting the MuC adapter 1, which is an external DC power supply, and the external power input terminal C is connected to the movable terminal of the first switch 3, which is a power on/off control switch, and the other fixed The terminal is voltage stabilization circuit 11
and is connected to the load circuit 12. Further, the external power input terminal C is connected to a positive terminal piece 8 which is connected to the positive terminal of a built-in power supply including a dry battery 6 and a storage battery 7, and a negative terminal piece 9 is connected to a second switch 4 which detects the presence or absence of the storage battery 7. The movable terminal is connected to the movable terminal, and the other fixed terminal is connected to the ground through the charging correction resistor 1o. In this case, a convex portion is provided on the storage case of the storage battery γ in order to distinguish between the dry battery 6 and the rechargeable storage battery 7, and this convex portion allows the second switch 40 to be
On/off driving is performed. Further, the negative terminal connection piece 9 of the built-in power supply is connected to the ground via a switch terminal piece B for detecting plug insertion of the external power supply provided in the external DC power input socket 2.

The operation of the power supply circuit configured as above will be described below.

(I) When driving a rechargeable storage battery (external DC power supply AC)
(When no adapter is supplied): When the storage battery γ is built-in, the charging voltage of the storage battery A is applied to the movable terminal of the first switch 3 via the positive terminal piece 8. At this time, if the first switch 3 is set to ON, the charging voltage is applied to the voltage stabilizing circuit 11 and the load circuit 12 via the other fixed terminal, and then passes through the ground to the switch of the external DC power input socket 2. A power supply circuit is driven through the terminal B and further through the negative terminal piece 9. In this case, the second switch 4, which detects the presence or absence of the storage battery 7, is in a short-circuited state because the storage electrons are built-in. Also, external DC power supply C
Since no output voltage is being supplied from the adapter 1, the switch terminal pieces M and B for detecting plug insertion of the external power source provided in the external DC power input socket 2 are also short-circuited.

(I[), When driving the external DC power supply C adapter (when there is no built-in rechargeable battery): If the output voltage of the external DC power supply C adapter 1 is supplied to the external DC power input socket 2, the DC input The voltage is applied to the movable terminal of the first switch 3, which is a power on/off control switch. When this first switch 3 is set to ON, the applied voltage is applied to the fixed terminal Kanakura, the voltage stabilizing circuit 11 and the load circuit 12.
The power supply circuit is activated via the ground and the switch terminal piece of the external DC power input socket 2.

In this case, since the storage battery T is not built-in, the second switch 4, which detects the presence or absence of stored electricity, is in a disconnected OFF state.

Problems to be Solved by the Invention However, in the above circuit configuration, when the circuit is driven by the external DC power supply AC adapter 1 with the storage battery 7 built-in, the output voltage of the external DC power supply AC adapter is , when the charging voltage of the storage battery is lower than the charging voltage of the storage battery 7: The charging voltage of the storage battery 7 is applied to the movable terminal of the first switch 3 via the positive terminal piece 8. At this time, if the first switch 3 is set to ON, the charging voltage of the storage battery 7 is applied to the voltage stabilizing circuit 11 and the load circuit 12 via the other fixed terminal, and is applied to the voltage stabilizing circuit 11 and the load circuit 12 via the ground. By being connected to the negative terminal piece 9 through the charging correction resistor 1o and the second switch 4, the circuit is activated by the charging voltage of the storage electrons even though it is driven by the external DC power supply AC adapter 1. The circuit operates as a discharge circuit contrary to the user's intention.

■When the output voltage of the external DC power supply AC adapter is higher than the charging voltage of the storage battery: The applied voltage supplied to the external DC power input socket 2 is applied to the movable terminal of the first switch 3, which is a power on/off control switch. applied. At this time, if the first switch 3 is set to ON, the applied voltage is applied to the voltage stabilizing circuit 11 and the load circuit 12 via the other fixed terminal, and then passes through the ground to the switch of the external DC power input socket 2. Normal circuit operation is performed through one terminal. Also, at this time, since the second switch 4 that detects the presence or absence of the storage battery 7 is set to a short-circuited state, the DC input voltage supplied to the external DC power input socket 2 is connected to the positive terminal connected to the positive terminal of the storage battery 7. is applied to piece 8. A charging circuit consisting of a second switch 4 and a charging correction resistor 10 is connected to the negative terminal piece 9, and connected to an external DC power supply AC adapter via the ground and one switch terminal of the external DC power input socket 2. 1, the charging current also flows into the storage battery 7, so that the circuit is driven as a charging circuit. From this, external DC power supply A
In addition to normal circuit operation, the AC adapter 1 also performs circuit operation as a charging circuit, so the power consumption increases accordingly, and the main body inevitably becomes larger and weighs more. It had all the problems of having to make it larger.

In view of the above-mentioned problems, the present invention has been developed to charge a rechargeable storage battery when a circuit is driven by an external DC power adapter with a built-in storage battery, and to discharge the charging voltage of the storage battery to a load circuit. It is an object of the present invention to provide a power supply circuit which can completely stop driving and which can be driven only by an external DC power supply adapter.

Means for Solving the Problems In order to solve the above problems, the power supply circuit of the present invention provides power on/off control between the second switch that detects the presence or absence of a rechargeable storage battery and the charging correction resistor. This is a new circuit configuration in which a third switch is newly provided which operates in conjunction with the first switch and which operates in reverse.

According to the present invention, with the above-described circuit configuration, the third switch is provided to operate in conjunction with the first switch for power on/off control and to operate in reverse, so that when the first switch is set to on, The third switch, which is connected between the charging correction resistor of the second switch that detects the presence or absence of the storage battery, is turned off, which allows the drive circuit for the storage battery to be completely disconnected, and the drive circuit for the storage battery to be disconnected. It is possible to reliably stop the charging/discharging circuit drive and put it into a non-operating state. For this reason, stable and normal circuit operation can be performed using only the input supply voltage applied from the AC adapter to drive the circuit of the power supply block, so it is possible to completely reduce power consumption as an AC adapter that is an external DC power supply. It becomes possible,
Since the main body shape can be made smaller, the M-C adapter can be made smaller and lighter.

Embodiment Hereinafter, a power supply circuit according to an embodiment of the present invention will be described with reference to all the drawings. FIG. 1 shows a wiring diagram of a power supply circuit according to an embodiment of the present invention. 2 is an external DC power input socket, the external power input terminal C is connected to the movable terminal of the first switch 3 which is a power on/off control switch, and the other fixed terminal is connected to the voltage stabilizing circuit 11 and the load circuit 12. Connected. Furthermore, the external power input terminal C is connected to a positive terminal piece 8 that is connected to the positive electrode of the storage battery 7, and the negative terminal piece 9 is connected to a movable terminal of a second switch 4 that detects the presence or absence of the storage battery 7. The other fixed terminal is connected to the fixed terminal of a third switch 5 which is provided to operate in conjunction with the first switch 3 for power on/off control and to operate in reverse, and the movable terminal is connected to the ground via a correction resistor 10 for charging. It is connected to 1. Further, the negative electrode terminal connection piece 9 of the storage battery 7 is connected to the ground via a switch terminal piece B/person for detecting plug insertion of an external power source provided in the external DC power input socket 2.

The operation of the power supply circuit configured as described above will be explained below using FIG. 1.

When driven by an external DC power source without a built-in storage battery,
The operation of the storage battery when the output voltage from the AC adapter, which is an external DC power source, is not supplied is the same as the circuit operation of the conventional example.

Next, when the circuit is driven by the external DC power supply module C adapter 1 with the rechargeable storage battery 7 built-in, the DC input voltage supplied to the external DC power input socket 2 is controlled to turn on and off the power. The voltage is applied to the movable terminal of the first switch 3, which is a switch for use. At this time, if the first switch 3 is set to ON, the applied voltage will not be applied to the voltage stabilizing circuit 11 and the load circuit 12 via the other fixed terminal, but will be applied to the switch of the external DC power input socket 2 via the entire ground. The power circuit starts up through one terminal. On the other hand, storage battery 7
The second switch 4, which detects the presence or absence of
The third switch 5 provided therebetween is connected to the first switch 3 for power on/off control and to operate in reverse, so the third switch 5 is turned off.

For this reason, the storage battery γ and the second switch 4. The charging/discharging drive circuit consisting of the third switch 5 and charging correction resistor 10 is completely disconnected, and has no relation to the output voltage supplied from the external DC power source C adapter 1 or the charging output voltage of the rechargeable storage battery 7. The charging/discharging circuit drive performed via the storage battery 7 is reliably stopped.

Effects of the Invention As described above, according to the present invention, a second switch that fully detects the presence or absence of a storage battery and a charging correction resistor is provided with a second switch that is interlocked with the first switch that is a power on/off control switch and that operates in reverse. By installing all three switches, the circuit can be operated by applying external DC power with the MuC adapter while the storage battery is built in. Even if this is done, the charging/discharging circuit of the storage battery can be completely stopped and put into a non-operating state regardless of the charging voltage of the storage battery, so it depends only on the input supply voltage applied from the AC adapter. , stable and normal circuit driving can be performed. From this, it is possible to reduce power consumption as an AC adapter that is an external DC power source, and the main body shape of the AC adapter can also be made smaller, making it smaller and lighter, which is an excellent effect. has.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a power supply circuit according to the present invention, and FIG. 2 is a circuit diagram showing a conventional power supply circuit. 1... External DC power supply AC adapter, 2...
...External DC power input socket, 3...1st
Switch (power on/off control switch), 4...
...Second switch (switch for storage battery detection), 6...
...Third switch, 6...Dry battery, 7...
...Storage battery, 8-...Positive terminal piece, 9...
・Negative terminal piece, 1o... Charging correction resistor, 11
...Voltage stabilization circuit, 12...Load circuit. 1st rXi,? Figure 2 ``Yukibanato Hill'' 10...Miko correction 8th hole If...Kazaan carving Kanraku I2...Saibada circuit

Claims (1)

[Claims] It has an external DC power input socket and a built-in battery terminal, and the external power input terminal to which the external power supply is connected is connected to the voltage stabilizing circuit and the load circuit via a first switch for power on/off control. The external power input terminal is connected to the positive terminal piece connected to the positive terminal of the storage battery, the other negative terminal piece is connected to one end of a second switch that detects the presence or absence of the storage battery, and the other end of this second switch is connected to the The second switch is connected to one end of a third switch that operates in conjunction with the first switch and operates in reverse, and the other end of the third switch is connected to ground via a charging correction resistor, and the negative terminal connection piece of the storage battery and the second switch are connected to each other. A power supply circuit characterized in that the connection point of is connected to a switch provided in an external DC power supply input socket for detecting plug insertion of an external power supply.