JPH0517802Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a backup power supply device including a backup power source such as a backup battery for a memory card.

(Prior Art) Memory backup circuits have been known that switch from an external power supply to a backup power supply and put the memory in a data retention state in order to read and write memory, that is, maintain the operating state of the memory during power outages. It is.

This conventional memory backup circuit connects a rectifier diode and a rush current prevention diode in parallel to an external power supply, and backs up the current to the external power supply in the forward direction of the rush current prevention diode. The battery was connected. and,
Given that the minimum operating voltage of a memory IC is 4.5V, the memory backup battery used was one rated to maintain 4.5V.

Incidentally, in recent years, it has become possible to back up memories with low voltage and minute current. For this reason, 3V lithium batteries, for example, have come to be used as long-life backup batteries.

(Problems to be Solved by the Invention) In this conventional backup power supply device, a circuit section including a backup battery and a voltage detection circuit and a power supply switching circuit connected thereto are connected by soldering lead wires. There is. Therefore,
If the voltage of the backup battery falls below a desired voltage, the circuit section must be discarded together with the battery even though the circuit section can still be used, which is disadvantageous in that it is uneconomical.

(Means for Solving the Problems) The object of the present invention is to eliminate the drawbacks of the prior art as described above and to provide an economical backup power supply device.

In order to achieve this purpose, the present invention includes a power supply storage part that can store a backup power supply in a replaceable manner;
A circuit capable of integrally housing and fixing a circuit unit having a voltage detection circuit connected to the backup power supply and an external power supply, respectively, and a power supply switching circuit that switches between the external power supply and the backup power supply according to a signal from the voltage detection circuit. A holder having a storage section is prepared.

A backup power source such as a lithium battery is replaceably housed in the power supply housing, and the circuit unit is integrally housed and fixed in the circuit housing by, for example, pouring synthetic resin into the circuit housing. The backup power supply and the circuit section are separably connected using, for example, a connector, so that when the voltage of the backup power supply falls below a predetermined voltage, only the backup power supply is replaced with a new one, and further, for example, the anode terminal of the backup power supply is replaced with a new one. The device is characterized in that a switching means is interposed between the terminal such as and the backup power input terminal of the device using the power source, or between the cathode terminal of the backup power source and the ground terminal of the device using the power source.

(Embodiment of the invention) Next, an embodiment of the invention will be described with reference to the drawings.

1 and 2 are wiring diagrams of a backup power supply device according to an embodiment.

In these figures, 1 is a voltage detection circuit, 2 is a power supply switching circuit, 3 is a backup battery such as a lithium battery, 4 is a main power input terminal, 5 is a power output terminal, 6 is a memory IC control signal output terminal, and 7 is a A ground terminal, 8 a battery anode terminal, 9 a battery input terminal, and 10 a battery cathode terminal.

FIG. 3 is a specific electrical circuit diagram of the wiring shown in FIG. 1. As shown in this figure, the voltage detection circuit 1 has a comparator IC1, and a memory
Due to the characteristics of the IC, a voltage corresponding to the minimum operating voltage of the memory IC is used as the reference voltage. This reference voltage and the main power supply voltage from the main power input terminal 4 are compared, and a rising signal or a falling signal is sent to the memory IC control board (not shown) via the power supply switching circuit 2 and the output terminal 6. is input. Further, the power supply switching circuit 2 includes resistors R1, R2,
Transistors Q1, Q2 and diode D1
It consists of In addition, this power supply switching circuit 2
A resistor R3 provided between the lithium battery 3 and the backup lithium battery 3 is a resistor for overcurrent protection.

1 and 3, during normal operation, the external power applied to the main power input terminal 4 passes through the power supply switching circuit 2 and is supplied to the memory IC from the power output terminal 5. At this time, an electric signal for activating the memory IC by the voltage detection circuit 1 is sent to the memory IC from the memory IC control signal output terminal 6, and the operative state of the memory IC is maintained.

Next, the operation when the external power supply is turned off will be explained.

Turning off the external power supply here may include a power outage or the power outlet being unplugged; in any case, it is necessary to switch to a backup power supply and put the memory IC into a data retention state. There is.

As mentioned above, when the external power supply is turned off due to a power outage, etc., the voltage detection circuit 1 detects that the main power supply voltage has fallen below the reference voltage, and the circuit is activated to put the memory IC into a non-operating state. The control signal is output from the memory IC control signal output terminal 6 to the control section of the memory IC. Further, when it is detected that the external power supply is turned off, a signal from the voltage detection circuit 1 is also input to the power supply switching circuit 2, whereby the external power supply is switched to the battery power supply, and the voltage of the battery 3 is changed to the power supply output terminal 5. is supplied to the memory IC.

When the external power applied to the main power input terminal 4 is restored, the voltage detection circuit 1 detects it and sends a control signal to the output terminal 6 to put the memory IC into operation.
is output to the control section of the memory IC, and
The power source switching circuit 2 switches from the battery power source to the external power source, and the memory IC becomes operational.

In the case of the wiring configuration shown in Figure 1, the battery anode terminal 8 and the battery input terminal 9 are separated, so that power cannot be supplied from the battery 3 unless they are electrically connected by a switch or the like. It's summery.

Further, in the case of the wiring configuration shown in FIG. 2, power cannot be supplied from the battery 3 unless the ground terminal 7 and the battery cathode terminal 10 are electrically connected.

If the wiring configurations shown in FIGS. 1 and 2 are used, the connection between the battery anode terminal 8 and the battery input terminal 9 can be cut off, for example, when shipping or transporting a product equipped with this backup power supply. Alternatively, if the connection between the ground terminal 7 and the battery cathode terminal 10 is cut off, unnecessary consumption of the battery 3 can be prevented.

4 to 8 are for explaining the structure of the backup power supply device according to the embodiment of the present invention. FIG. 4 is a vertical sectional view of the holder case body, and FIGS. 7 is a cross-sectional view taken along the line A--I in FIG. 6, and FIG. 8 is a cross-sectional view taken along the line RO--RO in FIG. 6.

This backup power supply device includes a lithium battery 21 used as a backup power source, a block-shaped circuit section 22 in which the voltage detection circuit 1, power supply switching circuit 2, etc. described above are packaged into one.
It is comprised of a holder 23 that accommodates the lithium battery 21 and the circuit section 22 in respective predetermined positions.

As shown in FIG. 5, the holder 23 is composed of a case body 23a and a lid body 23b that is removably attached to the opening of the case body 23a, and both the case body 23a and the lid body 23b are made of synthetic resin molded products. is made of. As shown in FIG. 4, the case body 23a is composed of a bottom part 24, a peripheral wall 25 erected from the periphery thereof, and a partition wall 26 erected from a predetermined position of the bottom part 24.

As shown in FIG. 4, the partition wall 26 divides the inside of the case body 23a into a large power supply storage section 27 and a small circuit storage section 28. As shown in FIG. In the bottom part 24 of the case body 23a, the power supply storage part 2
Terminal insertion holes 30 are formed at predetermined positions facing the terminals 7 and the circuit storage portion 28, respectively. Further, as shown in FIGS. 4 and 8, two terminal holding protrusions 29 are provided vertically on the inner surface of the peripheral wall 25 at a predetermined interval.

On the other hand, the power supply storage section 27 is located on the inner surface of the lid body 23b.
Four power supply holding pieces 31 are vertically disposed facing each other at a predetermined interval. Further, as shown in FIGS. 6 and 8, two terminal pressing protrusions 32 are formed vertically. Further, as shown in FIGS. 5 and 7, a curved leaf spring 33 is provided on the inner surface of the lid body 23b at a position facing the circuit storage portion 28, and has its elasticity so as to protrude downward. It is used and locked.

A cylindrical resin cover 34 protrudes from the center of one end of the lithium battery 21, and a cathode terminal portion 35 is provided along the circumferential surface of the resin cover 34. The part corresponding to the bottom of the lithium battery 21 facing this resin cover 34 is an anode terminal part 36 (see Fig. 8), and although not shown, a lead wire is soldered to this anode terminal part 36. connected.

On the other hand, the circuit section 22 is shaped like a block.
As shown in FIG. 7, a main power input terminal 4, a power output terminal 5, a memory IC control signal output terminal 6, and a ground terminal 7 are attached to the main power supply terminal 4, and each terminal 4 to 7 is connected to a terminal provided on the case body 24. It is inserted through the insertion hole 30 and led out. After inserting each of the terminals 4 to 7 into the terminal insertion hole 30 and positioning the circuit section 22 within the circuit storage section 28, the circuit section 22, the surrounding wall 25 and the partition wall 26 are inserted.
A resin layer 37 is formed by injecting and filling a synthetic resin such as urethane resin or epoxy resin into the gap. This allows the circuit section 22 to connect to the case body 2.
It is fixed integrally within the circuit housing portion 28 of 3a and is sealed with resin. As shown in FIGS. 5 and 6, a lead piece 38 is led out from the upper part of the circuit section 22 and extends toward the power supply storage section 27 side.

As shown in FIG. 8, the anode terminal plate 39
It is inserted and positioned between 9 and 29, and its terminal portion is inserted through the terminal insertion hole 30 and led out. A connector 40 is connected to this anode terminal plate 39 as shown in FIG.

The lithium battery 21 is inserted into the power supply housing part 27 of the case body 23a, to which the circuit part 22 and the anode terminal plate 39 are attached, in a state where the lithium battery 21 is laid down so that the resin cover 34 is on the side of the circuit housing part 28.
This insertion causes the cathode terminal portion 35 to be inserted under the free end of the lead piece 38. Also, lithium battery 21
One end of a lead wire (not shown) connected to the anode terminal portion 36 of is inserted into the connector 40,
It is electrically connected to the anode terminal plate 39.

Next, by fitting the lid body 23b into the opening of the case body 23a, the leaf spring 33 is inserted into the lead piece 38.
The free end of is firmly pressed against the cathode terminal portion 35 side, and the cathode terminal portion 35 is electrically connected to the ground terminal 7. In addition, by attaching the lid 23b, the lower end of the power presser piece 31 comes into elastic contact with the circumferential surface of the lithium battery 21, pressing the lithium battery 21 toward the bottom surface 24 of the case body 23a, thereby preventing the lithium battery 21 from shaking. are doing. Further, when the lid body 23b is attached, the upper end of the anode terminal plate 39 is pressed by the terminal holding protrusion 32 as shown in FIG.
9 rattling can also be prevented.

When the lithium battery 21 is used as a backup power source for an IC and its voltage drops below a predetermined level, the lid 23b is opened, the lead wire of the anode terminal 36 is disconnected from the connector 40, and the lithium battery 21 is removed from the case body 23a. Discard. Then, a new lithium battery 21 is set in the case body 23a in the same manner as described above, and used again.

Although a battery was used as the backup power source in the above embodiment, the present invention is not limited to this, and for example, a large capacity capacitor may be used as the backup power source.

Further, in the embodiment described above, a pressing contact method using a leaf spring was used for connection between the power supply section and the circuit section, but the connection using a connector may also be used. Furthermore, the backup power source and the anode terminal plate can be electrically connected by providing the aforementioned anode terminal plate with spring properties and elastically contacting one end of the anode terminal plate with the anode terminal portion of the backup power source. In short, any structure that makes it easy to replace the power source is sufficient.

(Effects of the Invention) The present invention has the above-mentioned configuration and is very economical because only the backup power supply needs to be replaced. Furthermore, since the circuit section is integrally fixed to the holder, the circuit section has increased impact resistance, eliminating troubles caused by impacts on the circuit section, and improving operational reliability.

Furthermore, since a switching means is interposed between the terminal of the backup power supply and the backup power input terminal of the equipment using the power supply, or between the cathode terminal of the backup power supply and the ground terminal of the equipment using the power supply, it is difficult to implement the backup power supply. By turning off the switching means when shipping or transporting the product, unnecessary consumption of the backup power source (battery) can be prevented.

[Brief explanation of drawings]

Figures 1 and 2 are wiring diagrams of a backup power supply according to an embodiment of the present invention, Figure 3 is a specific electrical circuit diagram of the wiring, and Figure 4 is a wiring diagram of a backup power supply according to an embodiment of the present invention. 5 and 6 are cross-sectional views and vertical sectional views of the backup power supply, FIG. 7 is a sectional view taken along the line E-A in FIG. 6, and FIG. FIG. 6 is a sectional view taken along the Ro-Ro line. 1... Voltage detection circuit, 2... Power supply switching circuit, 3
... Backup battery, 21 ... Lithium battery,
22...Circuit part, 23...Holder, 23a...Case body, 23b...Lid body, 26...Partition wall,
27...Power supply storage section, 28...Circuit storage section, 33
...Plate spring, 37...Resin layer, 40...Connector.

Claims (1)

[Claims for Utility Model Registration] A power supply storage part that can replaceably store a backup power supply, a voltage detection circuit connected to the backup power supply and the external power supply, and a signal from the voltage detection circuit to connect the external power supply and the backup power supply. A holder having a circuit storage part that can integrally house and fix a circuit part having a power supply switching circuit for switching between the two, a backup power source is replaceably stored in the power supply storage part, and the circuit part is stored in the circuit storage part. The backup power supply and the circuit section can be connected detachably by storing and fixing the backup power supply integrally with the circuit section, and connecting the terminal of the backup power supply and the backup power input terminal of the equipment using the power supply, or between the cathode terminal of the backup power supply and the equipment using the power supply. A backup power supply device characterized in that a switching means is interposed between a ground terminal and a ground terminal.