JP2780261B2 - Composite device power control circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control circuit when two devices controlled by a microcomputer are combined.

2. Description of the Related Art In a device using a microcomputer, devices developed for individual purposes are combined to improve convenience. At that time, the two devices are not only used as one unit, Sometimes I want to work individually. In addition to responding to such demands, it is possible to further enhance the convenience effect by compounding without losing the functions inherent in individual devices by making it possible for one to not work. Can be done. The present invention relates to a convenient power supply control circuit used for such a composite device.

When the individually developed devices A and B are combined into a single device, the power on / off of the device A is controlled by a microcomputer, and the power on / off of the device B is similarly controlled. The off is also controlled by the microcomputer, and when the microcomputer of the device A and the microcomputer of the device B are not configured as a system, the power switch of the device A and the power switch of the device B are separately provided when they are combined and integrated. There is a need. This means that since the power switches are separate, the power can be turned on and off individually even if they are integrated, so that they can be operated individually as needed. However, the fact that the power switches are separate is not coherent when viewed as a single device, and in most cases, the devices A and B are turned on and off at the same time, and in that case, if the power switches are separate, The on / off operation is required twice each time, and the operability is not good.

Therefore, in order to improve the operability by combining the separately developed devices A and B into one and improving the operability, a single power switch is provided so that both the devices A and B can be controlled on / off by one power switch. If one of the devices can be turned on and off irrespective of the other device, the unity as a unit can be exhibited and the operability is improved.

Problems to be Solved by the Invention However, if the control of the power supply of both devices is controlled by a microcomputer, and the microcomputers of both devices are not systematically coupled to each other, even if they can work individually, It is very difficult to control at the same time.

The present invention consolidates what was originally an individual device into a composite device, provides operability as a single device regardless of the functional aspects and the composite device, and provides the original single device. It is intended to be able to exhibit the function as a device.

Means for Solving the Problems In the present invention, in order to provide the function and operability as a single device while being a composite device, the basic power supply control is performed by operating one common switch. Must be able to do it. For this purpose, the present invention controls the power supply control signal (first switch) of one microcomputer to control, for example, to short-circuit a portion corresponding to a power switch constituted by a key matrix of the other microcomputer. The same operation as pressing the power switches of individual devices at the same time, and furthermore, the power control signal of the microcomputer, for example, the second switch is provided in the middle of the circuit that has the key operation of the other microcomputer. By providing a function as a single model while being a composite model by operating the second switch, it is possible to individually control the power supply.

Operation Therefore, according to the present invention, it is possible to supply power to all of the multifunction devices by operating the first switch, to supply power to only a specific device, and to use the second switch to supply power to a specific device. Power can be supplied to or stopped from only one device, and operability is greatly improved.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to a circuit configuration diagram.

In the figure, devices A and B are the basic devices of the composite model.
The device A has a microcomputer 1 for controlling a circuit. In the microcomputer 1, the Y and Z terminals constitute a part of a key matrix circuit. By short-circuiting between YZ with a power switch, a signal of a switch-on state (high level) and a signal of a switch-off state (low level) are alternately output from a power control terminal “X” of the microcomputer 1. . First, the voltage is partially connected to the base of the transistor Q1 through the resistor R2. When the power switch 2 is turned on (that is, at the high level), the base of the transistor Q1 is at the high level, and the voltage + B1 at the collector of the transistor Q1 is Zener diode D1 of appropriate voltage
After being controlled to a voltage determined by the following equation, the voltage becomes + B2 and is output to the load 3. The resistors R1 and R2 are bias resistors of the transistor Q1. The terminal X is connected from the anode of the diode D2 of the device B to each circuit of the device B through the resistor R3.

On the other hand, the device B also has a microcomputer, and its a and b terminals constitute a part of the key matrix circuit, similar to the Y and Z terminals of the microcomputer 1, and when the power switch 2 is pressed once, the terminal c goes high. When the terminal is pressed again, the terminal c becomes low level, indicating an off state.

The switch 5 has a common terminal connected to an intermediate terminal, which will be described later.

Now, when the power switch 2 of the microcomputer 1 of the device A is pressed,
The terminal X becomes high level and is applied to the base of the transistor Q2 from the anode of the diode D2 through the resistors R3 and R4.

 + B2 of device B is always "+" 5V.

When the base of the transistor Q2 goes high, the collector of the transistor Q2 goes low,
The base current of Q3 flows, the collector and emitter of transistor Q3 are short-circuited, and the microcomputer 4
Terminals a and b are short-circuited. When the terminals a and b are short-circuited, the terminal c becomes high level. When terminal c goes high, the voltage is applied to the intersection of resistors R10 and R11 and applied to the base of transistor Q10 through resistor R11.
And + B4 is generated. When + B4 occurs, power is supplied to the load 6, and the power is turned on.

When + B4 is applied, a voltage is applied to the base of the transistor Q4 through the resistor R6 to turn on the transistor Q4. When the transistor Q4 is turned on, the base of the transistor Q2 goes low, the collector of the transistor Q2 goes high, and the collector-emitter of the transistor Q3 is open. The state is maintained unless the next operation is performed.

On the other hand, the voltage applied to the anode of diode D2 is a resistance
The transistor Q6 is added to the base through R3, and the collector of the transistor Q6 goes low. However, the collector of the transistor Q7 remains at high level, and no change occurs.

Next, when the power switch 2 of the device A is pressed, the terminal X becomes low level. When it goes low, the base of transistor Q6 goes low, the collector of transistor Q6 goes high, transistor Q7 conducts, the collector goes low, and transistor Q8 conducts. When the transistor Q8 is turned on, the terminals a and b of the microcomputer 4 are short-circuited, and the terminal c becomes low level. Then, the transistor Q10 is turned off, so that + B4 also becomes low level. When + B4 becomes low level, power is not supplied to the load 6 of the device B, and the device 6 is turned off.
When + B4 goes low, transistor Q9 conducts, causing the collector of transistor Q6 to go low. Then, the collector of the transistor Q7 becomes high level, and the transistor Q8 is opened. The state is maintained unless the next operation is performed.

That is, the position of the common terminal of the SW switch 5 is in the open state.
By operating the power switch 2 of the device A, the power of the device B can also be turned on / off.

Next, if the common terminal of the switch 5 is set to the position,
The + B2 voltage is always applied to the common terminal through the resistor R9.
When + B2 is applied, it is applied to the base of the transistor Q2 through the resistor R4, the collector of the transistor Q2 becomes low level, the transistor Q3 is turned on, the a and b of the microcomputer 4 are short-circuited, the power is turned on, and the transistor Q1 is turned on.
Conducts 0 and generates + B4. When + B4 occurs, its voltage is applied to the base of transistor Q4 through resistor R6, causing transistor Q4 to conduct and bringing the base of transistor Q2 low. When the base of the transistor Q2 goes low, the transistor Q2 turns off, the collector voltage goes high, and the transistor Q3 turns off and stabilizes in that state. Now, when the power is turned off by operating the power switch 2 of the device A, the anode side of the diode D2 becomes low level, but since the common terminal is connected to the cathode side, + B2 voltage is always applied,
The power supply of the device B remains in the ON state, and has no relation to the power supply of the device A.

Next, the common terminal of the switch 5 of the device B is placed at the position. That is, the common terminal is grounded. Then device A
When the power switch 2 is operated and the terminal X goes high, the anode side of the diode D2 is grounded. The fact that the terminal of the switch 5 is at the ground potential means that the base of the transistor Q2 is grounded, the transistor Q2 is turned off, the collector is at a high level, and the transistor Q3 remains off. On the other hand, the base of the transistor Q6 is also grounded and the collector of the transistor Q6 is at the high level, but the microcomputer 4 of the device B remains off, the terminal c remains at the low level, and thus the transistor Q10 is off and + B4
Does not occur, the transistor Q9 is turned on, the collector of the transistor Q6 is set to low level, the transistor Q7 is turned off, and the transistor Q8 is kept off. That is, if the common terminal of the switch 5 is fixed to the ground potential, the power switch of the device A can be kept off regardless of whether it is on or off.

As described above, according to the present invention, when devices originally developed as individual devices are combined into one composite product from the viewpoint of convenience, individual microcomputers are apparently connected as a system, thereby improving operability. Can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a power supply control circuit of a multifunction device according to an embodiment of the present invention. 1, 4 microcomputer, 2 power switch (first switch), 3, 6 load, 5 second switch, Q1-Q10 transistors.

Claims (1)

(57) [Claims] A first circuit configured to control opening and closing of a power supply path from a DC power supply to a load circuit by a control signal from a control signal output terminal of the microcomputer;
A first input terminal for inputting a signal for controlling an open / close control signal output of a power supply path of the first and second electronic devices to a first microcomputer; A second input terminal for inputting to a microcomputer, and the first input terminal disposed between the second input terminal and an open / close control signal output terminal of a power supply path of the first electronic device.
Interlocking control means for simultaneously controlling the opening and closing of the power supply paths of the first and second electronic devices in conjunction with an input signal from an input terminal, and interlocking operation of the interlocking control means with the first and second electronic devices. In a multifunction device including an operation switching unit for switching to individual operation in the device, the microcomputer of the second electronic device is controlled by an open / close control signal of a power supply path output from the microcomputer of the first electronic device. The control is performed via the interlocking control means, and the operation of the second electronic device is controlled by the operation switching means regardless of the presence or absence of a power supply path opening / closing control signal from the microcomputer of the first electronic device. A power control circuit for a composite device, wherein the power control circuit is controlled by an input signal of an input terminal.