JPH0764652A - Back-up circuit - Google Patents

Abstract

PURPOSE:To secure the time required for holding the data by cutting or reducing the power supplied to each load excluding that of a data holding circuit if a power supply has a hit, a power failure or the drop of voltage level during the operation of an electronic equipment. CONSTITUTION:A control circuit 12 is provided with a function to apply various types of control to a controlled system and also to store the data on the relevent control contents in a hit or power failure state. A power failure detecting circuit 16 monitors the voltage of an AC power supply 1 and reports the hit or the power failure of the supply 1, if detected, to a regulator control circuit 17 and the circuit 12. The circuit 17 receives a detection signal from the circuit 16 and turns off the regulators 6, 7... to cut the supply of power to the unnecessary loads 14, 15.... At the same time, the circuit 12 uses the changed electric charge of a smoothing capacitor 4 as a back-up power supply to hold the required data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backup circuit capable of securing a necessary time for a backup power supply for holding data when an AC power supply is momentarily stopped or a power failure occurs during operation of electronic equipment. .

[0002]

2. Description of the Related Art Conventionally, some electronic devices have a backup power supply for holding data in the device when the AC power supply is momentarily interrupted or a power failure occurs during the operation of the device. In such a device, it is necessary to secure a backup power supply for a certain period of time or more in order to retain the data in the device in the event of a momentary power failure or power failure.

FIG. 6 is a block diagram showing a conventional backup circuit.

In FIG. 6, a voltage from an AC power source 1 such as a commercial AC power source is supplied to a primary coil of a power transformer 2, and the voltage of the secondary coil is rectified by a rectifying diode 3 and a smoothing capacitor 4. Rectified and smoothed.
This rectified voltage is supplied to a plurality of voltage stabilizing circuits (hereinafter, referred to as regulators) 5, 6, 7, ... While being supplied to a voltage detection circuit 11. The regulator 5 supplies electric power to the control circuit 12 and the backup capacitor 13, and the regulators 6, 7, ...
Power is supplied to 4, 15, .... The control circuit 12 performs various controls on a control target (not shown), and has a function of storing data representing control contents at the time of momentary power failure or power failure.

On the other hand, the voltage detection circuit 11 monitors the voltage of the smoothing capacitor 4 and, when the voltage of the capacitor 4 drops below a predetermined voltage, notifies the control circuit 12 of this. At this time, the control circuit 12 holds necessary data by using the charge of the backup capacitor 13 as a power source.

FIG. 7 is a block diagram showing another conventional example. In FIG. 7, an AC power source 21 such as a commercial AC power source
The voltage from is rectified by the full-wave rectifier circuit 22 of the diode bridge, further smoothed by the smoothing capacitor 23, and supplied to the switching type voltage stabilizing circuit (hereinafter referred to as a switching regulator) 24. The switching regulator 24 is configured, for example, to connect a switching element to the primary coil of an inverter transformer and control the ON time of the switching element so that the output voltage of the secondary coil becomes constant. The voltage output to the secondary side of the switching regulator 24 is rectified and smoothed by the diode 25 and the capacitor 26, and is supplied to the plurality of regulators 27, 28, 29, ....
The regulator 27 supplies power to the control circuit 32 and the backup capacitor 33, and the regulator 2
.. also supply electric power to the loads 34, 35 ,. The control circuit 32 is similar to the case of FIG.
Various controls are performed on a control target (not shown), and the control target has a function of storing data representing control contents at the time of momentary power failure or power failure.

On the other hand, the power failure detection circuit 31 detects an instantaneous power failure or a power failure of the AC power source 21 and informs the control circuit 32. At this time, the control circuit 32 holds necessary data by using the charge of the backup capacitor 33 as a power source.

FIG. 8 is an overall block diagram of a conventional satellite receiver having a built-in actuator drive circuit, and FIG. 9 is shown in FIG.
2 is a circuit block diagram for backing up the actuator position of the actuator control part in FIG. Here, the actuator drive circuit is a broadcasting satellite (B
S), a circuit for driving an actuator for moving and setting a communication satellite (CS) receiving antenna to a desired satellite position.

In FIG. 8, the voltage from the AC power supply 41 is supplied to a satellite receiver 42 with a built-in actuator drive circuit. From this receiver 42, the actuator drive voltage is connected to an antenna 43.
4 and the direction of the antenna 43 is changed. A signal indicating the actuator position is fed back from the actuator 44 to the receiver 42 to confirm the position, and the received signal from the antenna 43 is received by the receiver 4.
It is designed to be captured in 2.

The receiver 42 inputs the voltage of the AC power supply 41 and the power supply circuit 45 for converting the voltage of the AC power supply 41 into a DC voltage to generate an actuator drive voltage to generate an actuator 44.
To the actuator drive power source 4 and the actuator drive power source 4 based on the signal indicating the actuator position fed back from the actuator 44.
6, a control circuit 47 for supplying a drive control signal and a tuning control signal to the tuner unit 48, and a reception signal of the antenna 43 to perform tuning using the tuning data from the control circuit 47, while performing frequency conversion. And a tuner section 48 that performs detection, a video circuit 49 that generates a display video signal based on the detection output from the tuner section 48, and an audio circuit 50 that reproduces an audio signal based on the detection output from the tuner section 48. It consists of and.

Next, referring to FIG. 9, there is shown a circuit block diagram for backing up the actuator position of the actuator control portion in FIG.

In FIG. 9, the voltage from an AC power supply 61 such as a commercial AC power supply is supplied to the primary side coil of a power supply transformer 62, and the voltage of the secondary side coil is supplied by a rectifying diode 63 and a smoothing capacitor 64. Rectified and smoothed. This rectified voltage is supplied to a plurality of regulators 65, 6
, 67, ... While being supplied to the voltage detection circuit 71. The regulator 65 supplies power to the control circuit 72 and the backup capacitor 73, and the regulators 66, 67, ... Also have loads 74, 7 respectively.
5, ... Is supplying power.

On the other hand, the voltage detection circuit 71 monitors the voltage of the smoothing capacitor 64, and when the voltage of the capacitor 64 drops below a predetermined value, it notifies the control circuit 72. At this time, the control circuit 72 holds necessary data by using the charge of the backup capacitor 73 as a power source.

The control circuit 72 comprises a microcomputer 81, a non-volatile memory 82, and a volatile memory 83. The control circuit 72 drives and controls an actuator 93, which is one of the control targets, and when power is supplied, the control circuit 72 is operated at that time. The actuator position data is stored in the volatile memory 83, and the actuator position data at that time is stored in the non-volatile memory 82 in the event of a momentary power failure or power failure.
The nonvolatile memory 82 is, for example, an electrically erasable programmable ROM (EEPROM; ELECTRICALLY).
ERASABLE PROGRAMABLE ROM) is used. A random access memory (RAM) is used as the volatile memory 83, for example.

The microcomputer 81 outputs a control signal to the power supply control circuit 91. Based on this, the power supply control circuit 91 controls ON / OFF of the actuator drive power supply 92. When the driving power source 92 is turned on, the actuator 93 starts driving. The microcomputer 81 outputs the signal 94 from the actuator 93.
The position of the actuator 93 is grasped by.

Normally, when the AC power supply 61 is supplied, the actuator position data is stored in the volatile memory 83, and the data in the volatile memory 83 is rewritten every time the position of the actuator 93 is changed.

When the AC power supply 61 is momentarily stopped or has a power failure,
In response to the signal from the voltage detection circuit 71, the microcomputer 81 controls the power supply control circuit 91 to turn off, confirms that the actuator 93 has stopped based on the signal 94 from the actuator 93, and sets the actuator position to the nonvolatile memory 8
Store in 2. The power of the control circuit 72 is supplied by the backup capacitor 73 during the operation at the time of this momentary power failure or power failure.

By the way, in the case of each of the conventional circuits as described above, loads (14, 15 ..., 34, 35 ...) Or 74, 75 other than the control circuit (12, 32 or 72) at the time of power failure.
…) Is also working. For this reason, the charge (charge) of the capacitor (4, 23 or 64) used for smoothing is discharged quickly, so that the backup capacitor (13, 33 or 7) is discharged.
3) is added or smoothing capacitors (4, 2)
3 or 64), it is necessary to increase the capacity, and the circuit becomes large and the cost becomes high.

[0019]

As described above, in the case of the conventional circuit, the backup capacitor is required, and it is necessary to increase the time constant in order to secure the discharge time.

Therefore, in view of the above problems, the present invention secures a necessary time for a backup power source for holding data when the power source is momentarily stopped, a power failure occurs, or a voltage drop occurs while the electronic device is operating. The purpose of this is to improve the backup circuit.

[0021]

According to a first aspect of the present invention, there is provided a backup circuit including a power supply, a plurality of loads driven by the power supply, and a detection circuit for detecting an instantaneous power failure, a power failure or a voltage drop of the power supply. And means for shutting off or reducing the power supply to a load other than the circuit for holding data among the plurality of loads at the time of momentary power failure, power failure or voltage drop, using the detection signal from the detection circuit. It was done.

According to a second aspect of the present invention, there is provided a backup circuit comprising a power source, a plurality of loads driven by the power source, a detection circuit for detecting a momentary power failure of the power source, a power failure or a voltage drop, and an antenna direction. Actuator to change, and create a drive voltage based on the power supply,
One of a drive power source for driving the actuator and a load driven by the power source, and based on a detection signal from the detection circuit, data of an actuator position at the time of a momentary power failure, a power failure or a voltage drop. Means for interrupting or reducing power supply to a load other than the control circuit among the plurality of loads at the time of momentary power failure, power failure or voltage drop, using a control circuit held in the memory and a detection signal from the detection circuit It is equipped with and.

[0023]

According to the invention as set forth in claim 1, when the power source is momentarily stopped, a power failure or a voltage drop occurs during the operation of the electronic device,
This is detected by the detection circuit, and the detection signal is used to cut off or reduce the power supply to the loads other than the data holding circuit so that the power supply voltage can be supplied only to the data holding circuit. It is possible to secure the time to be considered.

According to the second aspect of the present invention, the detection circuit detects a momentary power failure, a power failure or a voltage drop of the power supply, and cuts off the supply of electric power to the unnecessary load by the detection signal from the detection circuit. In addition, the detection signal from the detection circuit notifies the control circuit that a momentary power failure, a power failure, or a voltage drop has occurred, and the control circuit saves actuator position data, for example. Since the supply of power to unnecessary loads is cut off or reduced, it is possible to secure time for backing up the control circuit that holds data such as the actuator position.

[0025]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing a backup circuit according to an embodiment of the present invention. The same parts as those in FIG. 6 will be described with the same reference numerals.

In FIG. 1, a voltage from an AC power supply 1 such as a commercial AC power supply is supplied to a primary side coil of a power supply transformer 2, and the voltage of the secondary side coil is supplied by a rectifying diode 3 and a smoothing capacitor 4. Rectified and smoothed.
This rectified voltage is supplied to the plurality of regulators 5, 6, 7, .... The regulator 5 supplies electric power to the control circuit 12, and the regulators 6, 7, ... Also supply electric power to the loads 14, 15 ,. The control circuit 12 performs various controls on a control target (not shown), and has a function of storing data indicating control contents at the time of momentary power failure or power failure.

On the other hand, the power failure detection circuit 16 monitors the voltage of the AC power supply 1, and when a momentary power failure or a power failure of the AC power supply 1 is detected, the regulator control circuit 17 and the control circuit 12 are detected.
Notify the occurrence of a momentary power failure or power outage. The regulator control circuit 17 and the regulators 6 and 7 constitute a power cutoff means. The regulator control circuit 17 receives the detection signal from the power failure detection circuit 16, and receives the regulators 6 and 7 ...
Is turned off, and the supply of power to the unnecessary loads 14, 15, ... Is cut off. At this time, the control circuit 12 uses the charge stored in the smoothing capacitor 4 as a backup power source to hold necessary data.

In the above configuration, when the power supply voltage is normally output from the AC power supply 1, the rectifier circuit (3, 3
4) and each regulator 5, 6, 7, ...
Power is supplied to 2, 14, 15, ....

Next, when the AC power supply 1 is momentarily stopped or has a power failure, the power failure detection circuit 16 detects an instantaneous power failure or a power failure of the AC power supply 1, and a detection signal from the detection circuit 16
The regulator control circuit 17 turns off the power supply paths of the regulators 6, 7, ... And shuts off the power supply to the unnecessary loads 14, 15 ,. On the other hand, during a momentary power failure or power failure,
The control circuit 1 is activated by the detection signal from the power failure detection circuit 16.
2 Inform the control circuit 12 that an instantaneous power failure or power failure has occurred.
Stores the necessary data by using the charge stored in the smoothing capacitor 4 as a power source. At this time, unnecessary loads 14, 1
Since the supply of electric power to 5, is cut off, the load on the smoothing capacitor 4 forming the rectifying circuit is lightened, and the discharge of the smoothing capacitor 4 is suppressed. Therefore, even if the capacity of the smoothing capacitor 4 is reduced, the time required for backing up the control circuit 12 that holds data can be secured. In this embodiment, the backup capacitor 13 in the conventional circuit (FIG. 6) can be deleted, and
Since the capacity of the smoothing capacitor 4 can be reduced, the circuit can be downsized and the cost can be reduced.

FIG. 2 is a block diagram showing a backup circuit of another embodiment of the present invention. It is an example when a switching regulator is used. The same parts as those in FIG.

In FIG. 2, a voltage from an AC power supply 21 such as a commercial AC power supply is rectified by a full-wave rectifier circuit 22 of a diode bridge, smoothed by a smoothing capacitor 23, and supplied to a switching regulator 24. The switching regulator 24 includes a switching element connected to the primary side coil of an inverter transformer, for example.
The ON time of the switching element is controlled so that the output voltage of the secondary coil becomes constant.
The voltage output to the secondary side of the switching regulator 24 is rectified and smoothed by the diode 25 and the capacitor 26, and the plurality of regulators 27, 28, 29, ...
Is supplied to. The regulator 27 supplies power to the control circuit 32, and the regulators 28, 29, ... Also supply power to the loads 34, 35 ,. Similar to FIG. 1, the control circuit 32 performs various controls on a control target (not shown), and has a function of storing data indicating the control content at that time in the event of an instantaneous power failure or a power failure.

On the other hand, the power failure detection circuit 31 monitors the voltage of the AC power supply 21, and when detecting a momentary power failure or a power failure of the AC power supply 21, the regulator control circuit 36 and the control circuit 3 are detected.
Report the occurrence of a momentary power failure or power outage to 2. The regulator control circuit 36, together with the regulators 28 and 29, constitutes a power cutoff means. The regulator control circuit 36 receives the signal from the detection circuit 31, and the regulators 28 and 29 ...
Is turned off, and the supply of power to unnecessary loads 34, 35, ... Is stopped. At this time, the charge of the primary side smoothing capacitor 23 of the switching regulator 24 is supplied to the control circuit 32 as a backup power source through the regulator 27, and the control circuit 32 thereby holds necessary data. There is.

In the configuration of FIG. 2, in the state where the power supply voltage is normally output from the AC power supply 21, the voltage rectified and smoothed by the rectifier circuit (22, 23) is switching-controlled by the switching regulator 24, Further, after being rectified and smoothed by the rectifier circuit (25, 26), the load 32, 34, 3 is passed through each regulator 27, 28, 29, ....
Power is supplied to 5, ...

Next, when the AC power supply 21 is momentarily stopped or has a power failure, the AC power supply 21 is immediately stopped or has a power failure.
1 and the detection signal from the detection circuit 31 causes the regulator control circuit 36 to control the regulators 28, 2
Turn off the power supply paths for 9, ...
Cut off the power supply to 5, ... On the other hand, at the moment of a power failure or power failure, the detection signal from the power failure detection circuit 31 informs the control circuit 32 that a power failure or power failure has occurred, and the control circuit 32 uses the charge stored in the smoothing capacitor 24 as a power source for the necessary data. However, at this time, since the power supply to the unnecessary loads 34, 35, ... Is cut off, the load of the smoothing capacitor 23 constituting the rectifier circuit is lightened, and the smoothing capacitor 23 is Discharge is suppressed. Therefore, even if the capacity of the smoothing capacitor 23 is reduced, it is possible to secure the time required for backing up the control circuit 32 that holds data. In this embodiment, the backup capacitor 33 in the conventional circuit (FIG. 7) can be deleted and the capacity of the smoothing capacitor 33 can be reduced, so that the circuit can be downsized and the cost can be reduced.

FIG. 3 is a block diagram showing a backup circuit of another embodiment of the present invention. The same parts as those in FIG. 2 will be described with the same reference numerals.

The embodiment of FIG. 3 is an AC power source 21 shown in FIG.
In place of the power failure detection circuit 31 that detects an instantaneous power failure or power failure, a voltage detection circuit 31A that monitors the output voltage of the smoothing capacitor 23 is provided. In the voltage detection circuit 31A, the rectified voltage from the smoothing capacitor 23 is compared with the reference value,
When the rectified voltage drops below a predetermined value, the detection signal informs the regulator control circuit 36 and the control circuit 32 of an instantaneous power failure or power failure of the AC power supply 21. The regulator control circuit 36 receives a signal from the voltage detection circuit 31A, limits the output voltage of the regulators 28A and 29A, ..., And reduces the supply of power to unnecessary loads 34, 35 ,. Here, unlike the regulators 28 and 29 of FIG. 2, the regulators 28A and 29A ... Increase the conduction resistance value of the output control transistor inside the regulator by the control signal from the regulator control circuit 36 at the time of momentary power failure or power failure. Controlled by the regulators 28A and 2
The output voltage of 9A ... Is limited. At this time, the control circuit 32 includes the switching regulator 2
The charge of the primary side smoothing capacitor 23 of No. 4 is supplied as a backup power source through the regulator 27, and the control circuit 32 holds necessary data by this. Other configurations are the same as those in FIG.

According to the configuration of FIG. 3, when the AC power supply 21 is momentarily stopped or has a power failure, this is detected by the voltage detection circuit 31A to limit the output voltage of the regulators 28A and 29A ... Since the power supply to the control circuit 32 is reduced, the backup power supplied to the control circuit 32 through the regulator 27 can be secured for a required time.

In place of the AC power supply 21 and the rectifier circuit 22 in FIG. 3, a DC power supply such as a battery or a battery is provided, and the voltage detection circuit 31A indicates that the power supply voltage has dropped below a predetermined value. Regulator 28 when detected
Cut off or limit (reduce) the output voltage of A and 29A.
It may be configured to do so.

FIG. 4 is a block diagram showing a backup circuit of another embodiment of the present invention. It is an example concerning the backup of the actuator position in the actuator control circuit. The same parts as those in FIG. 9 are designated by the same reference numerals for description.

In FIG. 4, the voltage from an AC power supply 61 such as a commercial AC power supply is rectified by a full-wave rectifier circuit 95 of a diode bridge, smoothed by a smoothing capacitor 96, and supplied to a switching regulator 97. The switching regulator 97 has a switching element on the primary side of the inverter transformer, for example, and is configured to control the ON time of the switching element so that the secondary side output voltage becomes constant. The voltage output to the secondary side of the switching regulator 97 is the diode 6
It is rectified and smoothed by 3 and the capacitor 64. This rectified voltage is supplied to the plurality of regulators 65, 66, 67, .... The regulator 65 supplies power to the control circuit 72, and the regulators 66, 67, ... Also supply power to the loads 74, 75 ,.

On the other hand, the power failure detection circuit 98 uses the AC power supply 61
Of the AC power supply 61 is detected, the detection signal notifies the regulator control circuit 99 and the control circuit 72 of the occurrence of the instantaneous power or power failure. The regulator control circuit 99, together with the regulators 66 and 67, constitutes a power cutoff means. The regulator control circuit 99 receives the detection signal from the detection circuit 98 and turns off the regulators 66 and 67 ...
The power supply to 4, 75, ... Is stopped. At this time, the control circuit 72 holds necessary data by using the electric charge charged in the capacitor 96 as a power source.

The control circuit 72 is composed of a microcomputer 81, a non-volatile memory 82 and a volatile memory 83. The control circuit 72 drives and controls an actuator 93 which is one of the control targets, and when the power is supplied, then The actuator position data is stored in the volatile memory 83, and the actuator position data at that time is stored in the non-volatile memory 82 in the event of a momentary power failure or power failure.
The nonvolatile memory 82 is, for example, an electrically erasable programmable ROM (EEPROM; ELCTRICALLY).
ERASABLE PROGRAMABLE ROM) is used. Further, as the volatile memory 83, an access random memory (RA
M) is used.

The microcomputer 81 outputs a control signal to the power supply control circuit 91. Based on this, the power supply control circuit 91 controls ON / OFF of the actuator drive power supply 92. When the driving power source 92 is turned on, the actuator 93 starts driving. The microcomputer 81 outputs the signal 94 from the actuator 93.
The position of the actuator 93 is grasped by the actuator, the actuator position data is stored in the volatile memory 83, and the actuator position data is stored in the non-volatile memory 82 in the event of a momentary power failure or a power failure.

In the configuration of FIG. 4, when the power supply voltage is normally output from the AC power supply 61, the voltage rectified and smoothed by the rectifier circuit (95, 96) is switching-controlled by the switching regulator 97, Further, after being rectified and smoothed by the rectifier circuit (63, 64), the load 72, 74, 7 is passed through the regulators 65, 66, 67 ,.
Power is supplied to 5, ...

Normally, when the AC power supply 61 is supplied, the actuator position data is stored in the volatile memory 83, and when the actuator 93 operates again, the microcomputer 81 reads the data in the volatile memory 83, The actuator 93 is operated, and after the actuator 93 is stopped, a new actuator position is stored in the volatile memory 83.

When the AC power supply 61 has a power failure, a signal from the power failure detection circuit 98 causes the regulator control circuit 99 to operate.
Turns off the regulators 66 and 67 .... On the other hand, the microcomputer 81 causes the actuator 93
During operation, the power supply control circuit 91 is turned off, the stop of the actuator 93 is confirmed based on the signal 94 from the actuator 93, and the actuator position is written in the nonvolatile memory 82 for backup. In addition, when the actuator 93 is stopped at the time of instantaneous power or power failure, the data in the volatile memory 83 is written to the non-volatile memory 82 for backup. During the operation at the time of this instantaneous power or power failure, the control circuit 72 is provided with the switching regulator 97.
The charged electric charge of the primary side smoothing capacitor 96 is supplied only to the control circuit 72 as a backup power source via the regulator 65. At this time, unnecessary loads 74, 75, ...
Since the supply of electric power to the smoothing capacitor 96 is lightened, the load on the smoothing capacitor 96 forming the rectifier circuit is lightened, and the discharge of the smoothing capacitor 96 is suppressed. Therefore, even if the capacity of the smoothing capacitor 96 is reduced, the time required for backing up the control circuit 72 that holds data can be secured. In this embodiment, the backup capacitor 73 in the conventional circuit (FIG. 9) can be deleted, and
Since the capacity of the smoothing capacitor 73 can be reduced, the circuit can be downsized and the cost can be reduced.

As a modification of FIG. 4, the microcomputer 81 may control the regulator control circuit 99 by a control signal upon receiving a signal from the power failure detection circuit 98 as shown in FIG.

In the above-mentioned embodiments, mainly the case of momentary power failure or power failure of the AC power supply has been described. However, in the present invention, unnecessary load is generated when the output voltage of the AC power supply drops below a predetermined value. In the present invention, when a direct current power supply such as a battery or a battery is used as the power supply, not only an alternating current power supply, but also a power failure or a voltage drop occurs Needless to say, the power supply to unnecessary loads may be cut off or reduced.

[0049]

As described above, according to the present invention, the time of the backup power source is reduced by detecting the instantaneous power failure, the power failure or the voltage drop and stopping or reducing the power supply to the unnecessary load. Can be secured.

[Brief description of drawings]

FIG. 1 is a block diagram showing a backup circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a backup circuit according to another embodiment of the present invention.

FIG. 3 is a block diagram showing a backup circuit according to another embodiment of the present invention.

FIG. 4 is a block diagram showing a backup circuit according to another embodiment of the present invention.

5 is a block diagram showing a modification of FIG.

FIG. 6 is a block diagram showing a conventional backup circuit.

FIG. 7 is a block diagram showing another conventional backup circuit.

FIG. 8 is an overall block diagram of a conventional satellite receiver with a built-in actuator drive circuit.

9 is a circuit block diagram for backing up an actuator position of an actuator control portion in FIG.

[Explanation of symbols]

1, 21, 61 ... AC power supply 3, 22, 95 ... Rectifying diode 4, 23, 96 ... Smoothing capacitor 5, 6, 7, 27, 28, 29, 65, 66, 67 ... Regulator 12, 32, 72 ... Control Circuits 14, 15, 34, 35, 74, 75 ... Loads 16, 31, 98 ... Blackout detection circuit 17, 36, 99 ... Regulator control circuit 31A ... Voltage detection circuit 28A, 29A ... Regulator

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G06F 12/16 340 H 9293-5B

Claims (2)

[Claims] 1. A power supply, a plurality of loads driven by the power supply, a detection circuit for detecting a momentary power failure, a power failure, or a voltage drop of the power supply, and a detection signal from the detection circuit, A backup circuit comprising: means for interrupting or reducing the power supply to a load other than a circuit for holding data among the plurality of loads when a power failure or a voltage drop occurs. 2. A power supply, a plurality of loads driven by the power supply, a detection circuit for detecting a momentary power failure, a power failure, or a voltage drop of the power supply, an actuator for changing the direction of the antenna, and a power supply based on the power supply. A driving power supply for driving the actuator by generating a driving voltage, and one of a load driven by the power supply, and based on a detection signal from the detection circuit, an instantaneous power failure, a power failure, or a voltage drop. At the time, a control circuit for holding the data of the actuator position in the memory and a detection signal from the detection circuit are used to supply power to a load other than the control circuit among the plurality of loads at the time of an instantaneous power failure, a power failure or a voltage drop. A backup circuit comprising means for interrupting or reducing the supply.