JPH06244699A - Power source throw-in device - Google Patents

Abstract

PURPOSE:To economize power consumption and to easily perform the cut-off of a power source. CONSTITUTION:This power source throw-in device provided with a power source switch circuit 4 for supplying the electric power of a power source 1 to a system 5 in the active state is provided with a power on a switch 2, first transistor Tr 1 for changing the power source switch circuit 4 to the active state by being electrified when the power source throw-in switch 2 is thrown in, second transistor Tr 2 for holding the active state of the power source switch circuit 4 by being electrified when the power source switch circuit 4 is turned to the active state, and third transistor Tr 3 for changing the Tr 2 to a non-electrified state by being electrified corresponding to a power supply cut-off signal 6. When the power supply cut-off signal is inputted through a push switch 3 or the system 5 to the Tr 3, the Tr 3 is turned to the electrified state and changes the Tr 2 into the non-electrified state. As a result, the power source switch circuit 4 is changed into the inactive state, and the supply of power to the system 5 is stopped. In such a state, the current flows neither to the respective transistors nor the power source switch circuit, and the battery is not consumed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power-on device used for portable electronic equipment and the like, and more particularly, it is configured to save current consumption.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional power-on device in a portable electronic device such as a portable personal computer or a mobile phone has a battery 1 used as a power source and an RS flip-flop circuit 7 for control. And a power switch circuit 4 for controlling whether or not power is supplied to the system 5.

When the power of the system 5 is turned on, the power-on signal 71 input to the set terminal S of the flip / flip circuit 7 becomes active, and when the power of the system 5 is turned off, the reset terminal of the flip / flip circuit 7 is turned on. The power cutoff signal 72 input to R becomes active. The power supply control signal 73 output from the Q terminal of the flip / flip circuit 7 becomes active when the power-on signal 71 becomes active, and becomes inactive when the power-off signal 72 becomes active. During that time, the power supply control signal 73 maintains the active state. When the power control signal 73 is active, the power switch circuit 4
Is activated and the system 1 is powered on,
On the contrary, when the power supply control signal 73 becomes inactive, the power supply switch circuit 4 becomes inactive and the system 5 is turned off.

In the initial state, the power of the system 4 is turned off, that is, in the cutoff state. At this time, the power control signal 73 is inactive and the power-on signal 73
Both 71 and the power-off signal 72 are inactive. When the power-on signal 71 becomes active in this state,
The RS flip-flop circuit 7 is set, and the power supply control signal 73 which is the output thereof becomes active. As a result, the power switch circuit 4 is activated and the system 5
Power is supplied from the power supply 1 to the.

After that, even if the power-on signal 71 becomes inactive, the output of the RS flip-flop circuit 7 keeps the power control signal 73 active to keep the set state, and the power of the system 4 remains It is kept in operation.

Next, it is assumed that the power of the system 4 is on, that is, the system 4 is kept in the on state. At this time, the power control signal 73 is active, and the power-on signal 71 and the power-off signal 72 are both inactive. In this state, when the power cutoff signal 72 becomes active,
The RS flip-flop circuit 7 is in the reset state,
The power supply control signal 73, which is its output, becomes inactive.
As a result, the power switch circuit 4 is deactivated and the power of the system 5 is cut off.

After that, even if the power cutoff signal 72 becomes inactive, the output of the RS flip-flop circuit 7 maintains the reset state, so that the power supply control signal 73 remains inactive and the power supply of the system 5 is kept. Keeps off.

Further, the system 5 is based on an automatic power-off signal for automatically shutting off the power supply when the equipment is not operated for a long time while the power supply is on, and the power supply voltage monitoring. Signals for shutting off the power are output, and these signals are input to the flip / flip circuit 7 as the power shutoff signal 72 to shut off the power to the system 5.

[0009]

However, in this conventional power-on device, when the battery 1 is attached, the RS flip-flop circuit 7 is always operated regardless of whether the system 4 is powered on or off. Therefore, the power of the battery 1 is consumed to maintain such a state, and accordingly,
There is a problem that the life of the battery 1 is shortened.

If a mechanical switch is used as a switch, the current can be completely cut off when the power is off. However, if the system is to have functions such as auto power off and power supply voltage monitoring, It becomes difficult to control the power cutoff with a mechanical switch.

The present invention solves these problems of the conventional device, and can save power consumption.
Another object is to provide a power-on device that can easily perform power-off control.

[0012]

Therefore, in the present invention, in a power-on device provided with a power supply and a power switch circuit for supplying the power of the power supply to the system in an operating state,
A power-on switch, a first transistor which conducts when the power-on switch is turned on to change the power switch circuit into an operating state, and a first transistor which conducts when the power switch circuit enters the operating state and holds the operating state of the power switch circuit There are provided a second transistor and a third transistor which is turned on by a signal for turning off the power and turns the second transistor to a non-conducting state.

[0013]

Therefore, when a signal for cutting off the power source is input to the third transistor through the push switch or the system, the third transistor becomes conductive and changes the second transistor to the non-conductive state. As a result, the power switch circuit changes to a non-operating state, and the supply of power to the system is stopped.

When the power supply to this system is off, no current flows through each of the transistors and the power switch circuit, and the battery is not consumed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a power-on device according to an embodiment of the present invention comprises a battery 1 used for power supply, a power-on switch 2 which is a push switch, and a power supply which is also a push switch. A cutoff switch 3 and a power switch circuit 4 for controlling the power supply from the power source 1 to the system 5 are provided, and further, a transistor Tr1 with a built-in resistor for switching which becomes conductive when the power-on switch 2 is pressed. , A transistor Tr2 with a built-in resistor for holding the power switch circuit 4 in an operating state, a pull-up resistor R1 connected between the output side of the power switch circuit 4 and the base side of Tr2, and power shutoff It has a transistor Tr3 with a built-in resistor for switching which becomes conductive when the switch 3 is pressed.

The power switch circuit 4 comprises a switching transistor Tr4 for switching the operating / cutting-off state of the power switch circuit 4, and current limiting resistors R2 and R3.

Further, the system 5 generates a control signal for shutting off the power source based on auto power off, power source voltage monitoring, etc., and the power source shutoff signal 6 is the transistor T.
Enter in r3.

This power-on device operates as follows.

In the initial state, the power of the system 5 is turned off, that is, in the cutoff state. At this time T
Each of r1, Tr2, Tr3 and Tr4 is in the cutoff state. Here, when the power-on switch 2 of the push switch is pushed down, Tr1 becomes conductive only while the switch 2 is pushed. When Tr1 becomes conductive, Tr4, which is low active, becomes conductive,
The power supply 1 is supplied to the system 5.

At the same time, Tr2 becomes conductive via the pull-up resistor R1. Therefore, even if the power-on switch 2 is released and, as a result, Tr1 is cut off, Tr4 is maintained in the conductive state and the power supply to the system 5 is continued.

Next, it is assumed that the power of the system 5 is on, that is, in the on state. At this time, Tr2 and Tr4 are in a conducting state, and Tr1 and Tr3 are in a blocking state. Here, when the power cutoff switch 3 which is a push switch is pushed down, the Tr3 becomes conductive only while being pushed. When Tr3 becomes conductive, Tr2 becomes cut off, and accordingly Tr4 also becomes cut off. Therefore, the power supply to the system 5 is stopped.

When the power cutoff signal 6 generated from the system 5 is input to the Tr3, the same operation as when the power cutoff switch 3 is pushed down is performed.

As described above, in the power-on device of the embodiment,
When the power of the system 5 is in the off state, the current does not flow, so the consumption of the battery 1 is saved.

[0024]

As is apparent from the above description of the embodiments, in the power-on device according to the present invention, when the power of the system is off, no current flows in any of the circuits, resulting in unnecessary power consumption. Since it is possible to save electricity, it is possible to extend the battery life.

It is also possible to cut off the power supply in response to a power supply cutoff signal issued from the system.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of a power-on device of the present invention,

FIG. 2 is a circuit diagram showing a configuration of a conventional power-on device.

[Explanation of symbols]

 1 battery 2 power-on switch 3 power-off switch 4 power-switch circuit 5 system 6, 72 power-off signal 7 RS flip-flop circuit 71 power-on signal 73 power-control signal

Claims (1)

[Claims] 1. A power-on device comprising a power supply and a power switch circuit for supplying the power of the power supply to a system when in an operating state, wherein the power-on switch and the power supply are electrically connected when the power-on switch is turned on. A first transistor that turns the switch circuit into an operating state, a second transistor that conducts when the power switch circuit enters an operating state and holds the operating state of the power switch circuit, and a transistor that shuts off the power supply And a third transistor for changing the second transistor to a non-conducting state.