JPH067453Y2 - Power interruption alarm circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a power interruption alarm circuit for preventing an outlet from being removed during a recording waiting period.

(B) Conventional Technology The program reservation television is configured to detect the arrival of the reservation time and receive the desired channel. However, the program reservation television has no meaning even if it operates during absence, and has a main power switch for prohibiting the operation during absence. This main power switch may be turned off only when the user is away, but there is a possibility that the main power switch may be set to remain off even at home.

In view of this, Japanese Patent Laid-Open No. 55-55631 discloses a configuration in which a warning sound is emitted to call the user's attention when the main power switch is still set to the OFF state when the reserved time arrives.

(C) Problems to be solved by the invention Although the video tape recorder has a reservation function similar to the program reservation TV mentioned above, it is not premised on that the user watches the program, so that the user does not have to turn on the main power switch each time. OFF
There is no state. However, there is a fear that a user who does not know that the video recording recorder is in the recording waiting state may accidentally unplug the outlet of the video tape recorder during the recording recording waiting period in order to save power. The recording reservation circuit of the video tape recorder composed of a microcomputer usually has a backup power supply as a countermeasure against power failure, so even if you accidentally disconnect the outlet,
It is structured so that the reservation waiting state can be maintained for about one year,
It is possible to adopt the configuration described above. However, even if the alarm sound is emitted when the reserved time arrives, the user cannot plug in the outlet while the user is away, and the problem cannot be solved even if the above-mentioned conventional technique is adopted in the recording reservation circuit of the video tape recorder.

(D) Means for Solving Problems Therefore, the present invention proposes a power cutoff alarm circuit suitable for a video tape recorder, which includes a backup power supply, an alarm sound generating means, a recording waiting output and a power supply. The present invention is characterized in that switching control means for inputting the cutoff output and connecting the backup power supply and the alarm sound generating means when both outputs are generated are provided.

(E) Operation According to the present invention, therefore, when the video tape recorder in the recording waiting state is accidentally unplugged, an alarm sound is immediately issued.

(F) Embodiment Hereinafter, an embodiment illustrated in the present invention will be described.

First, the present embodiment adopts the present invention to a video tape recorder having a recording reservation function, and FIG. 2 shows a functional circuit block diagram of a microcomputer constituting the recording reservation circuit.

As is clear from FIG. 2, the microcomputer (M) of this embodiment stores the setting information, which is set by the reservation operating means (1), including the reservation start time, the reservation channel, and the reservation end time in the memory (2). I remember. The setting information is also displayed on the external display means (3). The setting information and the real time information of the clock circuit (4) are input to the reservation execution circuit (5). The reservation execution circuit (5) generates a recording waiting output at the B terminal in the recording waiting state and is in an operating state, and when the actual time reaches the reservation start time, it selects the reserved channel information by the tuning circuit (6). ) To supply the recording start output to the system control circuit (7).
Supply to. As a result, the microcomputer (M) supplies the tuning output to the tuner (8) and the recording output to the recording means, and the recording of the desired channel is started at the desired time. Further, when the actual time coincides with the reservation end time, the supply of the reservation channel information is stopped and the recording end output is input to the syscon circuit (7). As a result, the tuner (8) finishes the channel selection and the recording means finishes the recording.

In the above-mentioned configuration, the microcomputer (M) receives the rectified 5V DC voltage at the A terminal as long as the outlet is inserted and the commercial power is supplied to the video tape recorder. The 5V first backup power supply, which will be described later, is in a charged state. Therefore, when the outlet is unplugged or a power failure occurs, the first backup power supply compensates the operation of the microcomputer for about one year.

FIG. 1 is a microcomputer showing the features of this embodiment.
The external circuit of (M) is shown. The rectified output of the power supply circuit is the first
It is supplied to the A terminal of the microcomputer (M) via the transistor (Q ¹ ) and the third transistor (Q ³ ). The collector of the second transistor (Q ² ) is connected to the base of the first transistor (Q ¹ ) via the first resistor (R ¹ ), and the rectified output terminal (T) has the second resistor (R ² ). Is input to the base of the second transistor (Q ² ) via. Further, the base of the third transistor (Q ³ ) is connected to the collector of the fourth transistor (Q ⁴ ) via the third resistor (R ³ ) and the base of the first transistor (Q 3
The collector output of ¹ ) is the fourth output via the fourth resistor (R ⁴ ).
It is connected to the base of the transistor (Q ⁴ ). Further, the collector output of the third transistor (Q ³ ) is
It is connected to the first backup power supply via a resistor (R ⁵ ). Therefore, as long as the rectified output is applied to the rectified output terminal (T), the first to fourth transistors (Q ¹ ) to (Q ^1
4 ) are all in the ON state, and the first backup power supply (V
¹ ) is in a charged state. This first backup power source (V
¹ ) is composed of nickel-cadmium batteries and its capacity is 10
It has a large capacity of 0 mAh, which is much larger than the current consumption of the microcomputer (M) of 10 μA, and can back up the microcomputer (M) for one year.

Therefore, after the rectification output is deenergized, the first to fourth transistors (Q
^{All of 1} ) to (Q ⁴ ) are turned off, and long-term backup is possible with the first backup power supply (V ¹ ).

On the other hand, the second backup power supply (V ² ) for alarm is the fourth
It is connected to the emitter of the transistor (Q ⁴ ) through the fourth resistor (R ⁴ ), and the fourth transistor (Q ⁴ ) is O
It is charged as long as it is in the N state. The emitter of the fourth transistor (Q ⁴ ) is connected via the seventh resistor (R ⁷ ) to the emitter of the fifth transistor (Q ⁵ ) which functions as switching control means, and the fifth transistor (Q ⁴ ) is connected.
The collector of ⁵ ) is connected to the collector of the seventh transistor (Q ⁷ ) which also functions as switching control means. Further, the collector of the sixth transistor (Q ⁶ ) is connected to the base of the fifth transistor (Q ⁵ ) via the ninth resistor (R ⁹ ). The recording standby output is connected to the base of the sixth transistor (Q ⁶ ) through the eighth resistor (R ⁸ ), and the fifth recording standby output is connected during the recording standby.
The sixth transistor (Q ⁵ ) (Q ⁶ ) is turned on. In addition, the base of the seventh transistor (Q ⁷ ) has a first
The rectified output is input through the 0 resistance (R ¹⁰ ),
The 7th transistor (Q
^The buzzer (B) connected in parallel with ⁷ ) is not energized. In order for the buzzer (B) to be energized by the second backup power source, the fifth transistor (Q ⁵ ) is turned on and the seventh transistor (Q ⁷ ) is turned off, that is, the commercial power source is turned on during the recording waiting period. Only when de-energized.
The second backup power source (V ² ) is also composed of a nickel-cadmium battery, its capacity is 25 mAh, and a buzzer with a current consumption of 15 mA can be operated for 10 minutes. If the buzzer sound in the above-mentioned embodiment is replaced with a voice announcement, a further effect can be expected.

(G) According to the effect of the invention, according to the invention, if the user accidentally unplugs the outlet during the recording waiting period, a buzzer sounds an alarm.
It is useful because it can alert the user.

[Brief description of drawings]

FIG. 1 shows a power supply circuit diagram showing an embodiment of the present invention, and FIG. 2 shows a circuit block diagram of a microcomputer of the same embodiment. (B) …… Buzzer, (V ² ) …… (Second) backup power supply, (M) …… Microcomputer.

Claims (1)

[Scope of utility model registration request] 1. A backup power supply and an alarm sound generating means,
A power cutoff alarm circuit for a video tape recorder, which is provided with switching control means for inputting a recording standby output and a power cutoff output and connecting the backup power supply and the alarm sound generating means when both outputs are generated.