JP2001175365A - Power source returning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely return a power source to any instantaneous interruption. SOLUTION: This power source returning device to use a replaceable battery as a main power source and to recover stopped operation when the operation of a main power source circuit to apply prescribed voltage to respective parts in equipment based on battery voltage is stopped due to instantaneous interruption of the battery voltage is provided with a clock, a backup power source for the clock and constituted so that a power on signal is repeatedly outputted to the main power source circuit by every prescribed time by the clock irrespective of an operating state of the main power source circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply recovery device for ensuring a power supply circuit to recover from an instantaneous interruption.

[0002]

2. Description of the Related Art A portable device such as a portable telephone mechanically removably couples a battery pack to a device body with a connector, and uses a battery of the battery pack as a main power source. As described above, since the battery pack is mechanically detachably connected by the connector, a phenomenon occurs in which the metal connection terminals of the connector are instantaneously disconnected from each other due to vibration of the device or the like. This is called instantaneous interruption. In a main power supply circuit for applying a predetermined voltage to each unit of the device according to the battery voltage, as shown in FIG. 4A, the battery power supply once drops below the voltage value (V-DET) and then returns to the voltage value (V-DE).
T) The power is turned on when a voltage higher than or equal to the voltage is applied, and a certain condition (for example, that the voltage of the capacitor for instantaneous interruption determination remains over a certain value, or that the instantaneous interruption state is stored in the internal memory, etc.) If the condition (2) is satisfied, it is determined that the power supply has been momentarily interrupted, and the power is kept as it is, and the normal operation is performed.

Such a prior art is disclosed in, for example,
No. 314552, "Power supply circuit". The invention disclosed in Japanese Patent Application Laid-Open No. 8-314552 discloses a method in which when a switch SW of the power-on switch circuit 2 is turned on as shown in FIG.
When the transistor switch of the power-on switch circuit 2 is turned on, the power supply voltage is supplied to the voltage detection circuit 4 and the impedance becomes high impedance, the differentiation circuit 5 generates a differentiation signal, and the transistor switch 6 is turned on for a certain time (100 ms). Start 3 With this activation, a stabilized power supply voltage is supplied to the CPU 7, and the CPU 7 outputs a power holding signal i to the main power supply circuit 3. Thereafter, the main power supply circuit 3 is driven by the power holding signal i.

[0004]

However, if the instantaneous interruption is restored in a very short time without the battery voltage dropping below the detection voltage (V-DET) as shown in FIG. 4 (b), the power is turned off. However, since the power-on switch circuit 2 is not turned on and the voltage detection circuit 4 does not operate, the power is not turned on again and remains off.

The present invention has been made in view of the above problems, and provides a technique for surely returning power to any momentary interruption.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention uses a replaceable battery as a main power source,
When a main power supply circuit that applies a predetermined voltage to each unit in the device based on the battery voltage stops operating due to an instantaneous interruption of the battery voltage, a power recovery device for recovering the operation includes:
A clock and a backup power supply for the clock;
The clock repeatedly outputs a power-on signal to the main power supply circuit at predetermined time intervals irrespective of the operation state of the main power supply circuit.

[0007]

FIG. 1 is a timing chart showing the principle of the present invention. (A) is the battery voltage, (b) is the supply voltage from the main power supply, and (c) is the real-time clock (R
TC). The RTC can output a signal at a set time, so that the power supply is turned on at regular time intervals during the operation. That is, during normal operation, even if the power ON operation is performed after the time T, the power is already ON and the operation is not changed. At this point, the automatic power-on function is reset after a time T from the current time. By repeating this operation, even if an instantaneous interruption occurs for a very short time and the main power supply circuit stops,
Power is turned on at the set time, and the main power supply circuit returns to operation. Therefore, the power is not kept off.

FIG. 2 is a block diagram of a power supply resetting device according to an embodiment of the present invention, in which an RTC 8 and a backup capacitor 9 are added to the power supply circuit described in the related art. According to this example, the CPU 7 sends the time setting signal j to the RTC 8 while the main power supply circuit 3 is operating with the power holding signal i. RTC 8 is a time setting signal j of CPU 7
The wake-up signal h is output at the fixed time interval T set in the above. In this state, if an extremely short-time interruption shown in FIG. 4B occurs, the CPU 7 also goes down due to the stop of driving of the main power supply circuit 3, but only the RTC 8 operates by the backup capacitor 9 and after a certain time T. An alarm signal h is output. Since the battery voltage 1 has already been recovered, the main power supply circuit 3 is activated again by the alarm signal h,
Therefore, the CPU 7 also returns to maintain the operation of the main power supply circuit 3 again with the power supply holding signal i.

Further, as another embodiment, the present invention can be applied to a logic circuit as shown in FIG. In the example of FIG.
7 outputs a power holding signal i, which is supplied to the OR
As the N signal k, the main power supply circuit 3 is operated to stabilize the battery voltage 1 to a predetermined voltage and to apply it to each section. The battery voltage 1 is monitored by the battery voltage detection circuit 4. In the normal momentary interruption shown in FIG. 4A, when the battery voltage 1 is restored, a detection signal g is output for a certain period of time. 3
Is turned on and the power is turned on. Thereafter, the CPU 7 outputs the power holding signal i.
The N signal k is held and the power remains on. FIG.
When the battery voltage detection circuit 4 cannot output the detection signal g due to the extremely short-time instantaneous interruption as shown in FIG. Since the signal is output every fixed time T regardless of the operation state of the power supply circuit 3, the power supply ON signal k is output from the OR circuit d, the main power supply circuit 3 returns, and the CPU 7 returns.

[0010]

As described above, according to the present invention, a replaceable battery is used as a main power supply, and a main power supply circuit for applying a predetermined voltage to each part in the apparatus based on the battery voltage operates by an instantaneous interruption of the battery voltage. A power restoration device for restoring the operation when the operation is stopped, comprising a clock and a backup power supply for the clock, wherein the clock is supplied to the main power supply circuit every predetermined time regardless of the operation state of the main power supply circuit. On the other hand, since the power-on signal is repeatedly output, the power can be reliably restored even if any momentary interruption occurs.

[Brief description of the drawings]

FIG. 1 is a timing chart showing the principle of a power return device according to the present invention.

FIG. 2 is a circuit diagram of a power return device according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a power return device according to another embodiment of the present invention.

4A and 4B show a detected voltage value at the momentary interruption of the battery power supply, wherein FIG. 4A is a diagram at the time of a normal momentary interruption, and FIG. 4B is a battery power supply at the time of an extremely short interruption targeted by the present invention. The figure which shows a voltage.

FIG. 5 is a circuit diagram of a conventional power return device.

[Explanation of symbols]

 1: Battery 2: Power-on switch circuit 3: Main power supply circuit 4: Voltage detection circuit 5: Differentiation circuit 6: Transistor switch 7: Control means (CPU) 8: Real-time clock (RTC) 9: Backup capacitor d: OR circuit g: detection signal h: alarm signal i: power holding signal j: time setting signal k: power on signal 1: battery voltage

Claims (1)

[Claims] When a main power supply circuit that uses a replaceable battery as a main power supply and applies a predetermined voltage to each unit in the device based on the battery voltage stops operating due to an instantaneous interruption of the battery voltage, the operation is restored. A power supply restoring device comprising a clock and a backup power supply for the clock, wherein the clock repeatedly outputs a power-on signal to the main power supply circuit at predetermined time intervals regardless of an operation state of the main power supply circuit. A power return device characterized in that: