JPH0537633Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is an AC power source that converts commercial power into DC power.
This invention relates to a power supply circuit suitable for devices using adapters, dry batteries that are non-rechargeable batteries, and rechargeable batteries.

(b) Prior Art Audio equipment called head-on stereo, which listens to signals reproduced from a magnetic tape by a head-on, is in widespread use, but since such equipment is used outdoors, it is difficult to use as a power source. Batteries are used. Such audio equipment is required to be ultra-miniaturized, but in that case, the size of the battery becomes a problem.
Recently, in order to solve this problem, devices have been developed that use rechargeable batteries of a special shape, for example a rectangular shape. In addition, when such audio equipment is used indoors, it can also be used with DC power supplied from an AC adapter that converts commercial AC power into DC power. The charging operation of a rechargeable battery is carried out by the above-mentioned technique, for example, as disclosed in Japanese Utility Model Application Publication No. 149939/1983.

(c) Problems to be solved by the invention The above-mentioned publication discloses a technique for supplying power to a load and charging a rechargeable battery using DC power supplied from an AC adapter. The device cannot be used outdoors if the rechargeable battery runs out of capacity. The present invention aims to provide a power supply circuit that is improved in this respect.

(d) Means for solving the problem The power supply circuit of the present invention includes an AC adapter plug that outputs a DC voltage obtained from an AC adapter that step-down rectifies a commercial AC power source, and a DC voltage that is obtained from a dry cell battery. A power jack having a positive terminal, a ground terminal, and a switching contact piece that is disconnected from the ground terminal when the AC adapter plug or the battery plug is inserted when a battery plug is inserted; a load to which DC power is supplied from the positive terminal of the switch via a power switch; a rechargeable battery connected between the positive terminal and the switching contact; a rechargeable battery connected between the switching contact and ground; The charging resistor limits the charging current of the rechargeable battery, and the switching switch is connected between the switching contact and ground and is closed when the battery plug is inserted into the power jack. ing.

(e) Effect This invention connects a rechargeable battery and a dry battery in parallel by short-circuiting both ends of a charging resistor with a changeover switch that is closed when a battery plug is inserted into a power jack. This is how it was done.

(f) Embodiment The circuit shown in FIG. 1 is an embodiment of the power supply circuit of the present invention, and FIG. 2 is a perspective view showing the relationship between the dry cell battery and the main body of the audio equipment. In FIG. 2, 1 is the main body of the audio equipment in which a drive mechanism of a tape recorder, an amplifier circuit, etc. are incorporated, and 2 is a battery storage container in which dry batteries 3 are stored and is used in conjunction with the main body 1. , a battery plug 4 through which a DC voltage obtained from the dry battery 3 is output, and a switching protrusion 5 are formed. Reference numeral 6 refers to a power supply through hole formed on the lower surface 7 of the main body 1 into which an AC adapter plug is inserted into which the DC voltage obtained from the battery plug 4 and the AC adapter is output; This is a switching hole formed on the lower surface 7 and into which the switching projection 5 is inserted when the battery storage container 2 is combined with the main body 1. In FIG. 1, 9 is the power supply through hole 6 in the main body 1.
This is a power jack that is placed at a position corresponding to the battery plug 4 and the AC adapter plug, and into which the battery plug 4 and the AC adapter plug are inserted. A switching contact piece 12 is provided which is disconnected from the ground terminal 11 when the plug is in the inserted state. 13 is a power switch; 14 is a load such as an electric motor or an amplifier circuit constituting the tape recorder; the positive terminal 1 of the power jack 9 ;
0 through the power switch 13 so that DC power is supplied thereto. Reference numeral 15 denotes a rechargeable battery housed in the main body 1, the positive terminal of which is connected to the positive terminal 10 of the power jack 9 , and the negative terminal connected to the switching contact piece 1.
Connected to 2. 16 is the power jack 9
This is a charging resistor connected between the switching contact 12, that is, the negative terminal of the rechargeable battery 15, and the ground, and has the function of limiting the charging current during the charging operation of the rechargeable battery 15. 17 is a changeover switch connected between the changeover contact piece 12 of the power jack 9 and the ground, that is, in parallel with the charging resistor 16;
When the battery plug 4 is inserted into the power jack 9 by combining the battery holder 2 and the battery holder 2, the battery holder 2
The switching protrusion 5 formed in the switching hole 8 is inserted into the switching hole 8 to be closed. The power supply circuit of the present invention is constructed as described above, and its operation will be explained next.

First, we will explain the power supply operation using the AC adapter. AC installed in AC adapter
When the adapter plug is inserted into the power jack 9 , the positive terminal and negative terminal provided on the plug connect to the positive terminal 10 provided on the power jack 9.
and is connected to the ground terminal 11 and the switching contact piece 1
2 is separated from the ground terminal 11. In this state, a direct current obtained from the AC adapter flows to the rechargeable battery 15 through the positive terminal 10, the rechargeable battery 15, the charging resistor 16, the ground wire and the ground terminal 11, and the rechargeable battery 15 is charged. will be carried out. The charging resistor 16 is set so that an excessive current does not flow through the rechargeable battery 15 while such a charging operation is being performed. The rechargeable battery 15 is charged in this manner, and when the power switch 13 is closed in this state, the DC voltage obtained from the AC adapter is transferred to the load 1 through the power switch 13.
4, and each operation of the tape recorder can be performed. And in such a state, AC
Adapter capacity for load 14 and rechargeable battery 15
If the setting is made in consideration of the capacity of the load 14, the charging operation of the rechargeable battery 15 can be performed at the same time while supplying power to the load 14.

As described above, the operation of supplying power to the load 14 and the operation of charging the rechargeable battery 15 by the AC adapter are performed. Next, the operation of supplying power by the rechargeable battery 15 charged in this manner will be explained. When the AC adapter plug and battery plug 4 are not inserted into the power jack 9 , the switching contact piece 12 is in contact with the ground terminal 11, and the positive terminal of the rechargeable battery 15 is connected to the positive terminal 10. At the same time, the negative terminal is installed via the switching contact piece 12 and the ground terminal 11. When the power switch 13 is closed in such a state, the DC power obtained from the rechargeable battery 15 is supplied to the load through the power switch 13, allowing various operations of the tape recorder to be carried out.

As mentioned above, AC adapter and rechargeable battery 15
The power supply operation is carried out using the following.Next, the operation when using dry batteries will be explained. Such an operation involves storing the dry battery 3 in the battery container 2 as shown in FIG.
This is done by combining with. When the battery storage container 2 is combined with the main body 1, the battery storage container 2
A battery plug 4 and a switching protrusion 5 provided on the main body 1 are inserted into a power supply hole 6 and a switching hole 8 formed on the lower surface 7 of the main body 1, respectively. As a result, the battery plug 4 is inserted into the power switch 9 , and the changeover switch 17 is closed. When the battery plug 4 is inserted into the power jack 9 , the positive terminal and negative terminal provided on the battery plug 4 are connected to the positive terminal 10 provided on the power jack 9 .
and is connected to the ground terminal 11 and the switching contact piece 1
2 is separated from the ground terminal 11. In this state, the positive terminal of the rechargeable battery 15 is connected to the positive terminal 10, and the negative terminal is connected to the ground terminal 11 via the changeover switch 17 and the ground wire.
Therefore, the rechargeable battery 15 and the dry battery 3 are connected in parallel to the load 14. Therefore, if the power switch 13 is closed in such a state, the DC power obtained from the rechargeable battery 15 and the dry battery 3 will be supplied to the load. Further, when the voltage of the rechargeable battery 15 is lower than the voltage of the dry battery 3 when such an operation is performed, the rechargeable battery 1 is charged by the current supplied from the dry battery 3.
5 charging is performed.

In this embodiment, the opening and closing operations of the changeover switch 17 are performed by the changeover protrusion 5 formed on the battery container 2, but the battery plug 4 and
It is also possible to configure the power jack 9 to operate in the same way as the changeover switch 17 by making the shape of the AC adapter plug different and incorporating a switch whose switching operation is controlled by the difference in shape into the power jack 9. I can do it. In addition, rechargeable battery 15
is removable from the main body 1, and the rechargeable battery 1
If the AC adapter plug or battery plug 4 is inserted into the power jack 9 with the AC adapter 5 removed from the main body 1, power can be supplied to the load 14 without any trouble.

(g) Effects of the invention The power supply circuit of the invention uses a changeover switch that closes when the battery plug is inserted into the power jack into which the AC adapter plug and the battery plug are inserted, and when charging the rechargeable battery. The rechargeable battery and the dry battery are connected in parallel by short-circuiting both sides of the charging resistor, which is connected in series to limit the charging current. This makes it possible to extend the lifespan of rechargeable batteries and dry cell batteries, and when the capacity of the rechargeable battery runs out, the dry cell battery can be replaced by inserting the battery plug into the power jack that presses the DC voltage obtained from the dry cell battery. This makes it possible to supply power to the load, making the present invention ideal as a power supply circuit for ultra-small audio equipment.

[Brief explanation of the drawing]

The circuit shown in FIG. 1 is an embodiment of the power supply circuit of the present invention, and FIG. 2 is a perspective view showing the relationship between the dry cell battery and the main body of the audio equipment. Explanation of main drawing numbers, 1...Main body, 2...Battery container, 3...Dry battery, 4...Battery plug, 5...
Switching protrusion, 9 ...Power jack, 10...Positive terminal, 11...Grounding terminal, 12...Switching contact piece, 1
3... Power switch, 14... Load, 15... Rechargeable battery, 16... Filling resistor, 17... Changeover switch.

Claims (1)

[Scope of utility model registration request] An AC adapter plug that outputs a DC voltage obtained from an AC adapter that step-down rectifies a commercial AC power supply, and a battery plug that outputs a DC voltage obtained from a dry battery are inserted, and a positive terminal, a ground terminal, and the AC adapter are inserted. a power jack having a switching contact piece that is disconnected from the ground terminal when a battery plug or a battery plug is inserted; and a load to which DC power is supplied from the positive terminal of the power jack via a power switch. , a rechargeable battery connected between the positive terminal and the switching contact piece, a charging resistor connected between the switching contact piece and ground and limiting the charging current of the rechargeable battery, and the switching contact piece. a changeover switch connected between the contact piece and ground and closed when a battery plug is inserted into the power jack;
A power supply circuit characterized in that when a battery plug is inserted into a power supply jack, the changeover switch is closed to short-circuit both ends of the charging resistor, thereby connecting the rechargeable battery and the dry battery in parallel.