JPH0441531Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a power supply circuit for a storage device that erases data held in the storage device when the lid of the case housing the storage device is opened. It is related to.

(Prior art) A CATV converter for receiving pay broadcasting is equipped with a circuit that descrambles scrambled broadcast signals, and only the subscriber can operate the descrambling circuit normally to receive pay broadcast programs. is configured to receive. The operation of this descramble circuit is controlled based on data provided from the music side.
Since this data is changed as necessary, it is stored in a rewritable storage device such as static RAM. This storage device also stores a user identification code that has nothing to do with receiving paid broadcasting. In order to prevent anyone other than the reception subscriber from modifying the CATV converter in order to illegally receive paid broadcast programs, when the CATV converter cover is opened, the power supply to the storage device from other sources is cut off. It is configured so that the stored data is erased.

FIGS. 3 and 4 show a conventional power supply circuit for a storage device that cuts off power supply from other sources to the storage device when the lid is opened. FIG. 3 is an external view thereof, and FIG. 4 is an electric circuit diagram.

In FIGS. 3 and 4, printed circuit board 1
A non-lock type switch 2 consisting of a lever switch or the like is disposed at the top, and a boss 5 is protruded from a lid 4 facing a lever 3 provided on the switch 2. Then, the switch 2 is linked to the opening and closing of the lid 4,
When the lid 4 is opened, the contact 2a of the switch 2 is opened, and when the lid 4 is closed, the contact 2a is closed, and this contact 2a is interposed in series between the power supply 6 from another source and the storage device 7. Therefore, when the lid 4 is opened, the power supply 6 of the storage device 7 is cut off, the stored data is erased, and the CATV converter becomes unable to receive not only pay broadcasts but also service broadcasts.

(Problems to be Solved by the Invention) By the way, in the case of the power supply circuit of the conventional storage device described above, the lid 4 is opened during shipping tests or service inspections, so the switch 2 is Contact 2a is opened. Therefore, while the lever 3 of the switch 2 is forcibly pushed down and the contact 2a is closed, test data is stored in the storage device 7 and various tests or inspections and adjustments are performed. When the shipping test or service inspection is completed in this way, the forced depression of the lever 3 of the switch 2 is released and the lid 4 is closed. Here, when the lever 3 of the switch 2 is released from being pressed down before the lid 4 is closed, the contact 2a of the switch 2 is opened and the power supply 6 is once cut off. For this reason, the test data in the storage device 7 disappears, and in order to close the lid 4 and perform the final operation test, the test data must be stored in the storage device 7 again, which increases the effort and effort. There was a problem with that.

The purpose of this invention was to solve the above-mentioned problem with the conventional power supply circuit of a storage device, and the power supply to the storage device is cut off even with the lid open during shipping tests or service inspections. First, there is provided a power supply circuit for a storage device in which the power supply is cut off when the lid is once closed and the lid is opened again.

(Means for Solving the Problems) In order to achieve the above object, the power supply circuit for a storage device of the present invention is an electronic device equipped with a storage device whose memory is retained by power supplied from another source. a first switch whose contacts close when the lid is closed in conjunction with the opening/closing operations of the lid of the case housing the storage device; and a first switch which opens the contacts when the lid is opened; A second switch whose contacts open when the lid is closed is provided, the first switch and the second switch are connected in parallel and interposed between the power supply and the storage device, and the lid is closed. After the contacts of the first switch are closed by the closing operation, the contacts of the second switch are opened.

(Function) The first switch, which is linked to the opening/closing operation of the lid of the case housing the storage device, closes the contact when the lid is closed, and opens the contact when the lid is opened, and the first switch, which is linked only to the closing operation of the lid. A second switch whose contacts open when the lid is closed is connected in parallel and interposed between the power supply and the storage device, and after the first switch is closed when the lid is closed, the second switch is connected in parallel. Since the switch is opened, during shipping tests or service inspections, close the second switch, connect the power supply to the storage device, and work with the lid open. When the switch is closed, the first switch is closed and the second switch is opened. Closing the first switch maintains the connection between the storage device and the power supply. Therefore, the test data does not disappear from the storage device when the lid is closed, as in the conventional case. Moreover, when the lid is opened again, both the first switch and the second switch are open, and the power supply to the storage device is cut off, making it possible to erase the data in the storage device.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an external view of one embodiment of the power supply circuit of the storage device of the present invention, and FIG.
The figure is an electrical circuit diagram of FIG. 1. In FIGS. 1 and 2, the same members as those in FIGS. 3 and 4 are given the same reference numerals and redundant explanations will be omitted.

In FIGS. 1 and 2, printed circuit board 1
A non-lock type first switch 2 consisting of a lever switch etc. and a lock type second switch 12 consisting of a slide switch etc. are arranged adjacent to each other. The knob 13 of the switch 12 is pressed down. Here, when the lever 3 is pushed down, the first switch 2 switches to the contact 2a.
is opened, and when the lever 3 is released from being pressed down, the contact 2a is closed. Furthermore, when the knob 13 is not pressed down (the knob is in the solid line position in FIG. 1), the contact 12a of the second switch 12 is closed and the knob 13 is pressed down.
When the knob is pressed down (the knob is in the position indicated by the broken line in FIG. 1), the contact 12a is opened. Furthermore, lever 3
By pressing down, contact 2 of first switch 2
After a is closed, contact 1 of the second switch 12
2a is opened.

The contacts 2a and 12a of the first and second switches 2 and 12 are connected in parallel and interposed in series between the power supply 6 and the storage device 7.

With this configuration, when the lid 4 is opened for a shipping test or a service inspection, the work can be carried out with the knob 13 of the second switch 12 in the position indicated by the solid line in FIG. 1, with the contact 12a closed. . When the lid 4 is closed at the end of the work, the lever 3 of the first switch 2 is pressed by the boss 5.
This lever 3 causes the knob 1 of the second switch 12 to
Press down on 3. As a result, the contact 2a of the first switch 2 is closed, and then the contact 12a of the second switch 12 is opened, maintaining the connection between the power supply 6 and the storage device 7, and data is stored. Saved.

In this state, when the lid 4 is opened again, the second
The knob of the switch 12 remains in the position indicated by the first broken line and the contact 12a is opened, and the contact 2a of the first switch 2 is opened in conjunction with the lid 4. Therefore, the power supply 6 and the storage device 7 are cut off, and the data in the storage device 7 disappears.

In the above embodiment, the knob 13 of the second switch 12 is pushed down by the lever 3 of the first switch 2, but the knob 13 of the second switch 12
3 may of course be directly pushed down by the boss 5 of the lid 4.

(Effect of the invention) As explained above, the power supply circuit for the storage device of the invention closes the second switch to connect the power supply to the storage device and closes the lid during shipping tests or service inspections. When working with the lid open and closing the lid when the work is completed, the first switch is closed and the second switch is opened.
Closing the switch maintains the connection between the storage device and the power supply. Therefore, the test data does not disappear from the storage device as in the conventional case. Moreover, when the lid is opened again, both the first switch and the second switch are open, and the power supply to the storage device is cut off, making it possible to erase the data in the storage device. Therefore, during shipping tests or service inspections, there is no need to forcibly press down the switch lever as in conventional circuits, and the test data only needs to be memorized once. Furthermore, since the second switch is opened by closing the lid, there is an excellent effect that even if the lid is opened due to an operational error or the like, there will be no problem in which the power supply and the storage device will not be cut off.

[Brief explanation of the drawing]

FIG. 1 is an external view of one embodiment of the power supply circuit of the storage device of the present invention, FIG. 2 is an electric circuit diagram of FIG. 1, and FIG. 3 is a conventional power supply circuit diagram of the storage device. FIG. 4 is an external view of the supply circuit, and FIG. 4 is an electrical circuit diagram of FIG. 3. 2...First switch, 2a, 13a...Contact, 4...Lid, 6...Power supply, 7...Storage device, 12...Second switch.

Claims (1)

[Scope of utility model registration request] An electronic device that is equipped with a storage device whose memory is retained using power supplied from another source, and when the lid is closed in conjunction with the opening/closing operation of the lid of a case housing the storage device, a contact closes and the lid is closed. A first switch that opens the contact when opened, and a second switch that opens the contact when the lid is closed in conjunction with only the closing operation of the lid, and the first switch and the second switch are connected to each other. The switch is connected in parallel and interposed between the power supply and the storage device, and the contact of the second switch is opened after the contact of the first switch is closed by an operation of closing the lid. 1. A power supply circuit for a storage device, comprising: