JP2591814Y2 - External power supply - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external power supply connected to a portable device such as a camera.

[0002]

2. Description of the Related Art Conventionally, batteries have been used as internal power supplies for portable devices such as cameras. For example, a standard type of camera incorporates an AA battery therein. As described above, since the standard type has a small amount of charge, the number of images to be photographed may be relatively small. Therefore, instead of the internal power supply of the portable device described above, an external power supply device connected to the device is used. As such, an external power supply device including a battery such as a single battery or an electric circuit for supplying power to the above-described portable device using the battery is used.

However, when the output terminal of the external power supply device is short-circuited due to mischief or the like, a large current exceeding the maximum rated current value of the external power supply device is applied to the electric circuit of the external power supply device. The flow causes the battery and the electric circuit of the power supply device to generate heat, and the battery and the electric circuit may be damaged. In addition, if the input terminal is short-circuited due to mischief or the like to the input terminal before the output terminal is connected to the input terminal of the portable device, the current of the maximum rating of the external power supply is A large current exceeding the value flows into the electric circuit of the power supply device, and the flow generates a danger that the battery or the electric circuit of the power supply device generates heat and the battery or the electric circuit is damaged. .

Further, if a wiring failure occurs for some reason in an electric circuit disposed inside the above-mentioned portable device,
A short circuit (short circuit) may occur in the electric circuit, and in such a case, the above-described large current flows in the electric circuits of the external power supply device and the portable device. The battery of the device, and the electric circuit of the power supply device and the portable device generate heat, and each electric circuit and the battery are damaged.

A maximum rated current value is predetermined for the external power supply device, and when the current value exceeds the maximum rated current value, the current is called a large current. When a large current flows through the electric circuit of the device, the respective electric circuits and the batteries of the external power supply generate heat, and there is a risk of being damaged. Furthermore, even if the motor provided inside the camera tries to rotate by receiving the output current of the external power supply device, it cannot rotate, for example, far exceeding the total number of frames already photographed on the film. However, for some reason, when the winding motor attempts to wind the film, and when the end of the film is locked to the rotating shaft inside the patrone, even if the winding motor tries to rotate, the film is not rotated. The above-described locking may cause an abnormal state in which the hoist motor cannot be rotated while the hoist motor is on. At this time, the current from the external power supply device is supplied to the above hoist motor via the camera. Flowing through the coil of
A state close to a short circuit occurs. Due to this state, the above-described large current may flow in the respective electric circuits of the external power supply device and the portable device, and due to this flow, similarly to the above, the respective electric circuits and the external power supply The battery generates heat and is damaged.

Conventionally, in order to prevent these dangers, a protection circuit such as a circuit breaker or a fuse is provided in an external power supply device, and the protection circuit uses the protection circuit to provide an electric circuit of the portable device or an electric power supply of the external power supply device. Protects circuits and batteries. The above-described protection circuit operates when a large current exceeding the maximum rated current value of the external power supply device flows to the electric circuit of the external power supply device, detecting the large current.

[0007]

However, when the above-mentioned large current does not flow, for example, when the voltage of the external power supply decreases due to long-term use of the battery provided in the external power supply, the output of the external power supply is reduced. If the output terminals of the external power supply are short-circuited due to short-circuiting of the terminals or having a certain resistance value, a current slightly smaller than the above-mentioned maximum rated current is supplied to the electric circuit of the external power supply. Will flow. Although the current is slightly smaller than the maximum rated current value as described above, if the current flows through the electric circuit of the external power supply device for a long time, the external power The electric circuit and the battery of the apparatus generate heat, and the electric circuit and the battery may be damaged.

Accordingly, the present invention has been made in view of the above-mentioned problems, and in addition to the above-described large current, even if a current slightly smaller than the maximum rated current value of the external power supply flows through the electric circuit of the external power supply. Another object of the present invention is to prevent the electric circuit of the power supply device and the electric circuit of the portable device from being damaged, and to prevent the battery provided in the external power supply device from being damaged.

[0009]

In order to solve the above-mentioned problems, according to the present invention , an external power supply (1) is provided with a power supply (8).
Accommodating the accommodating chamber, and an electrical circuit (12, 13) for feeding a current from the power supply means to the outside, outside by the power supply unit
A plurality of detecting means for detecting a temperature of the storage chamber during parts feeder (14), based on the temperature detected by the detecting means
Limiting means (14) and the setting for limiting the current from the power unit
And a plurality of detecting means, which are diagonal to each other in the accommodation room.
It was configured to be arranged at each end .

[0010]

When a current slightly smaller than the maximum rated current value of the external power supply flows through the electric circuit of the external power supply for a long time due to the short circuit or the like, and the above-mentioned large current flows through the electric circuit. Then, the power supply means (battery) connected to the electric circuit generates heat. Due to the heat generated by the power supply means, the internal temperature of the external power supply changes (rises). If the temperature change before dangerous detecting means for detecting, said restricting means based on the detected known, the so limits the current from the power supply means, a current value slightly less current and preceding larger than the maximum rating of above current does not flow in the electric circuit or external, it is possible to prevent the external power supply or damage the external device for that. Also, by arranging the detection means on the diagonal line,
Detects the internal temperature regardless of the posture of the power supply unit
Can increase the reliability as a safety device.
I can do it.

[0011]

FIG. 1 is a schematic perspective view showing an example of a camera system in which an external power supply 1 according to the present invention can be connected to a camera 2. FIG. In FIG. 1, a camera 2 is provided with a photographing lens 3, and a subject image obtained by the lens 3 can be viewed through a viewfinder 4. The power supply of the camera 2 is an AA battery which is an internal power supply (not shown),
The external power supply 1 can be used.

The external power supply 1 is connected to a cord 20. When the connector 6 of the cord 20 is inserted into the connector receiving portion 5 of the camera 2, the AA battery inside the camera 2 is supplied to the camera 2. It is separated from the electric circuit in the camera,
An external power supply 1 is electrically connected to the camera 2. The external power supply 1 formed in a box shape has a battery storage room 1 therein.
A plurality of single batteries 8 are stored in 9, and the single batteries 8 can be replaced by opening the lid 7. The springs 21a and 21b inside the lid 7 are terminals that come into contact with the electrodes of the single cell 8 in a state where the lid 7 is closed, and are configured to press the single cell 8 in the battery storage room 19. is there.

FIG. 2 is a circuit diagram showing respective electric circuits of the external power supply device 1 and the camera 2 according to the present invention. As shown in the figure, the electric circuit surrounded by the block 1 on the left side shows the electric circuit provided inside the external power supply device 1 in FIG. 1, and the electric circuit surrounded by the block 2 on the right side 1 shows an electric circuit provided inside. An electric circuit in the camera 2 includes, as shown in the block 2, an exposure control circuit 9 for controlling the exposure of the camera, and a display circuit 10 for displaying data in the camera such as a shutter speed and an aperture value. And a drive circuit 11 for driving a motor for auto-focusing, film feeding, etc., and the electric circuit of the external power supply 1 is used as a power supply as shown inside the block 1. A plurality of D-cells 8 and an air circuit breaker 14 also used as a temperature detecting element
And a regulator 12 used as a constant voltage power supply circuit
And an overcurrent detecting resistor 13.

As is well known, the connector 6 of the cord 20 of the external power supply 1 has respective terminals including a hollow cylindrical portion and a concentric cylindrical portion located in the hollow. The portion 5 has respective terminals including a first hollow cylindrical portion and a second hollow cylindrical portion located in the hollow, and the connector 6 of the cord 20 is inserted into the connector receiving portion 5 of the camera 2. Then, the connection terminals 5a and 6a in FIG. 2 corresponding to the hollow cylindrical portion of the connector 6 and the first hollow cylindrical portion of the connector receiving portion 5 are connected to each other, and the concentric cylindrical portion of the connector 6 and the connector receiving portion. The connection terminals 5b and 6b in FIG. 2 corresponding to the second hollow cylindrical portion of the portion 5 are also connected to each other. By this connection, the electric circuit in the block 1
It is used as a circuit for supplying power to the electric circuit of the camera 2.

The overcurrent detecting resistor 13 located inside the block 1 is for converting the current flowing from the battery 8 into a voltage, and the regulator 12 is provided with an overcurrent limiting circuit inside. I have. When the overcurrent limit circuit exceeds the maximum rated current value of the external power supply,
The current is limited, that is, the above-described resistance 1
When the voltage value of 3 becomes equal to or more than a predetermined value, the overcurrent limiting circuit limits the current under the control of the regulator 12 itself.

As described above, when a short circuit occurs in the output terminal of the external power supply device or a short circuit in the camera occurs, the voltage value exceeds a predetermined value due to the resistor 13 described above. Control
The internal overcurrent limiting circuit limits the current, but limits the current beyond the maximum rating, so that a large current (large current) still flows.

If the overcurrent limiting circuit does not operate for some reason, an extremely large current will flow more than when the above-mentioned limiting is performed. The absolute circuit interruption is performed by the air circuit breaker 14 in FIG. The details are as follows. Due to the short circuit or the like described above, a current slightly smaller than the current value of the above-described maximum rating is applied to the external power supply device 1.
Even if the above-described large current flows through the electric circuit of the external power supply device 1 for a long time,
The battery 8 generates heat due to its internal resistance, and due to the generated heat, the room temperature of the battery storage chamber 19 in FIG. 1 rises. The air circuit breaker 14 detects this temperature rise and shuts off the circuit by itself. The air circuit breaker 14 may be any circuit breaker, thermostat, or the like as long as the circuit can be shut off by sensing the temperature.

FIG. 3 shows a thermostat used as the air circuit breaker 14. The cylindrical temperature detecting portion 15 located on the right side in FIG.
3 are provided and are not disclosed in the figure,
One contact piece 22 is connected to the terminal 17 via the main body 14a, and the other contact piece 23 is connected to the terminal 18.
The above-mentioned contact piece 23 is formed of a bimetal in which two kinds of metals having different coefficients of thermal expansion are bonded to each other, and together with one piece 22 forms a kind of switch that bends depending on temperature.

At normal low temperatures, the respective sections 22, 23
And the terminals 17 and 18 are short-circuited by this contact. When the ambient temperature rises, the section 23 is bent by the bimetal structure and separates from one of the contact pieces 22. This separation opens the terminals 17 and 18, and also opens the air circuit breaker 14 in FIG. (OFF) state.
Due to this conversion, the current flow of the electric circuit in the block 1 is interrupted, so that a current slightly smaller than the above-mentioned maximum rated current value or the above-mentioned large current flows to all the circuits in FIG. And all the circuits and the battery 8 can be prevented from being damaged. Therefore, the thermostat 14 of FIG. 3 is also used as a temperature detecting element and the above-mentioned shutoff means. The screw hole 16 in FIG.
4 is fixed with screws (not shown).

FIG. 4 shows the battery storage chamber 19 of the external power supply 1.
FIG. 2 is a schematic perspective view showing a posture when the external power supply device 1 is actually used, and is shown in a state when the external power supply device 1 is hung on a shoulder of a photographer by a strap (not shown) or the like. Let's say The battery storage chamber 19 holds the single cell 8
Are arranged in two rows of three vertically and a total of six are included.
A partition 24 is provided between each row so that these batteries can be properly accommodated in the battery storage chamber 19. Springs 25 and 26 are attached as electrodes to the lower part of the battery storage chamber 19 in the drawing. The thermostat 14 is installed above the partition 24 in the figure. This is because when the room air in the battery storage room 19 is heated by the heat generated by the single cell 8 and convection occurs, Of these, the heat is concentrated in the upper part of the figure, so that it was installed at this location.
In addition, as long as the rise in the room temperature of the battery storage room 19 can be detected by the heat generation of the single battery 8, it is not necessary to install the partition 24 above the drawing, and it may be installed anywhere.

FIG. 5 shows the thermostat 14 in FIG.
FIG. 4 is an enlarged view of a part around the installation position, and the thermostat 14 is fixed to a partition 24 by a screw 27 in FIG. 5 through a screw hole 16 in FIG. 3. In order to detect an increase in the room temperature of the battery storage chamber 19 due to the heat generated by the single cell 8, the thermostat 14 is attached so that the temperature detection portion 15 of the thermostat 14 is exposed from the cutout portion of the partition 24 shown in FIG. 5. I have. This is to allow the room air heated by the heat generated by the single cell 8 to efficiently hit the temperature detecting portion 15 of the thermostat 14.

In FIG. 5, the cutout portion is provided. However, there is no problem in mounting the cutout portion as long as the method can reliably detect an increase in the room temperature, for example, by providing a vent hole and mounting the cutout portion inside the cutout portion. . Although not shown in FIGS. 4 and 5, the overcurrent detection resistor 13 and the regulator 12 in FIG. 2 are provided inside the partition 24 in FIG.
One of the terminals 17 is connected to a terminal 25 in FIG. 4 through a connection cord (not shown) provided inside the partition 24, and FIG.
The other terminal 18 is connected to the above-described overcurrent detection resistor 13 located inside the partition 24. Its resistance 13
The other end of the above-mentioned regulator 12 connected to the above-mentioned regulator is connected to the above-mentioned central cylindrical portion (connection terminal 6a) located at the connector 6 of the above-mentioned cord 20, and the other terminal 26 in FIG.
Are connected to the concentric cylindrical portion (connection terminal 6b) formed on the connector 6 of the cord 20. The respective terminals 21a and 21b located inside the lid 7 in FIG. 1 are electrically connected by connecting pieces (not shown).

FIG. 6 shows the battery storage room 19 of the external power supply device 1.
FIG. 2 is a schematic perspective view showing an embodiment in which two thermostats 14 are provided in the embodiment. As shown in this figure, a thermostat 14 is provided above one inner wall of the battery storage chamber 19, and another thermostat 14 is provided below one end of a diagonal line passing through that portion, that is, below the other inner wall. I have. The circuit at this time is such that another air circuit breaker 14 is inserted between the battery 8 and the air circuit breaker 14 shown in FIG. 2 so that the two air circuit breakers are connected in series. Except for the individual air circuit breakers 14, the same as described above.

When the above-mentioned single cell 8 generates heat, at least one of the two air circuit breakers 14 detects an increase in the room temperature, and the contact piece 23 in FIG. Piece 22
In order to cut off the flow of current away from the power supply, a current slightly smaller than the maximum rated current value or the large current described above flows through the electric circuit of FIG. However, it is possible to prevent the electric circuit and the battery 8 from being damaged.

According to the above-described embodiment, the temperature detecting element is also used as the shut-off means as described above. However, in another embodiment, the temperature detecting element may be separately provided. Instead of the circuit breaker 14, a movable switch is provided, and the movable switch and a control unit that controls opening and closing of the movable switch constitute the above-described blocking unit. The temperature detecting sensor may be installed inside the wall, and instead of the thermostat 14 shown in FIG.

The movable switch is turned on in advance by the control unit, and the battery 8 is turned on by the short circuit.
When the heat is generated, the room temperature of the battery storage room rises, and the control unit opens (turns off) the movable switch by the above-described temperature detection sensor.
Needless to say, a current slightly smaller than the maximum rated current value or the above-described large current stops flowing, and the above-described electric circuit and the like can be protected.

As described above, a camera is used as a portable device, and a single-cell battery is used as an external power source.
The present invention is not limited to the above embodiment,
As an external power source, a storage battery such as a car battery and a portable device such as a video camera which can be operated by the battery are used. In this case, a battery storage room for storing the battery and the battery storage room An external power supply device provided with a temperature detecting element provided in the chamber, an electric circuit for supplying power to the above-described device by a battery, and the above-mentioned shutoff means may be provided, and the operation may be performed as follows.

When a short circuit or the like occurs in at least one of portable equipment such as a video camera and the above-mentioned external power supply for some reason, if the above-mentioned battery generates heat, it is provided in a battery storage room of the battery storage. The above-mentioned temperature detecting element detects an increase in the room temperature of the battery storage room, and the above-mentioned shut-off means cuts off the flow of current in the internal circuit of the external power supply device. The current that is slightly smaller than the maximum rated current value of the external power supply or the large current described above does not flow through the electric circuits of the external power supply and the portable device, preventing damage to the electric circuit and the battery. can do.

Further, a protection circuit such as a circuit breaker or a fuse is not provided in FIG. 2, but as another embodiment, an electric circuit in the block 1 in FIG.
The above-described protection circuit may be provided, and when the above-mentioned large current flows, the above-mentioned protection circuit cuts off the flow of the large current, or the air circuit breaker 14 generates the large current as described above due to heat generation of the battery. If the current is interrupted, or if a current slightly smaller than the maximum rated current flows for a long time,
As described above, if the aerial circuit breaker 14 interrupts the current flow due to the heat generated by the battery, it does not hinder the purpose of the present invention.

[0030]

According to the present invention as described above EFFECT detects the temperature change of the internal external power supply device, since it is configured to limit the current to the power supply circuit of the internal if any abnormal temperature, the external power supply device Internal damage and damage to the power supply can be prevented. In addition, since the current flowing to the outside of the external power supply is also limited, it is possible to prevent the external devices connected to the power supply from being damaged. In addition, detection means are arranged diagonally.
The internal power supply, regardless of the attitude of the external power supply.
Since the temperature of the section can be reliably detected,
Reliability can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a camera system according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a circuit arranged inside an external power supply device 1 and a camera 2 in FIG.

FIG. 3 is a schematic perspective view of a thermostat used as an example of a temperature sensing element.

FIG. 4 is a schematic perspective view of the external power supply according to the embodiment of the present invention;

FIG. 5 is an enlarged perspective view showing the temperature detecting element 14 and its periphery in FIG.

FIG. 6 is a schematic perspective view of an external power supply when two temperature sensing elements 14 are provided in a battery storage chamber 19 according to another embodiment of the present invention.

[Explanation of symbols]

1 ... External power supply device 2 ... Camera 8 ...
・ AAA battery 14 ・ ・ ・ Temperature detecting element, 19 ・ ・ ・ Battery storage room

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02J 7/00-7/10 H02J 7/34-7/35

Claims (2)

(57) [Scope of request for utility model registration] An accommodation circuit for accommodating power supply means , an electric circuit for supplying current from the power supply means to the outside, and a plurality of detection means for detecting a temperature in the accommodation chamber when the power supply means supplies power to the outside. , based on the temperature detected by the pre-dangerous detecting means, possess a limiting means for limiting the current from the power supply means, said plurality of detecting means includes a diagonal to each other of the accommodating chamber
An external power supply device, wherein the external power supply device is disposed at both ends . 2. The method according to claim 1, wherein the detecting means collects heat in the accommodation room.
2. The device according to claim 1, wherein the device is disposed at a middle position.
3. The external power supply according to 1.