JPS6346660B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power supply device for equipment using a microcomputer, etc., and an object of the present invention is to provide an excellent power supply device that can save power with a simple configuration. .

Generally, when supplying power to each circuit block in a device using a microcomputer or the like, a dedicated stabilizing power supply circuit is often used for each circuit block. In other words, the first circuit block, which consumes a large amount of current in a short period of time, such as a microcomputer, and the second circuit block, which includes a timer, RAM, etc. that must be constantly energized, are connected through a common stabilized power supply circuit. In the case of a configuration in which a predetermined power supply is supplied using a stabilized power supply circuit, a relatively large capacity is required as a stabilized power supply circuit, and the power consumption by the stabilized power supply circuit becomes extremely large. Therefore, conventionally, stabilized power supply circuits are formed separately, and the first circuit block, which consumes a large amount of current in a short period of time, is configured to be turned on only when necessary. However, even in this case, the second circuit block, which includes a timer, RAM, etc. that must be constantly energized, enters a so-called operating state under the control of the first circuit block, which consumes a large amount of current in a short period of time. Since the power supply circuit is often constructed as follows, it is necessary to prepare a stabilized power supply circuit with a considerably large capacity for the second circuit block, which is still not sufficient in terms of power saving.

The present invention eliminates the above-mentioned conventional drawbacks, and provides an excellent power supply device that has a simple configuration and is advantageous in power saving.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The power supply device of the present invention will be described below with reference to drawings of an embodiment. In the figure, 1 is an external power supply terminal, 2 is a battery, 3 is a first stabilized power supply circuit, 4 is a first circuit block, 5 is a second stabilized power supply circuit, and 6 is a second circuit block.

Note that the first stabilized power supply circuit 3 is a transistor.
Q ₁ , Q ₂ , resistors R ₂ , R ₃ , R ₄ , diode D ₄ , and Zener diode D ₃ , and the second stabilized power supply circuit 5 includes transistors Q ₃ , Q ₄ ,
It consists of Q ₅ , resistors R ₆ , R ₇ , R ₈ , R ₉ , and diode D ₆ . The first circuit block 4 includes a timer circuit, RAM, keyboard, etc., and the second circuit block 6 includes a microcomputer, etc. Although not shown, the first circuit block 4 and the second circuit block 6 are connected to each other by a bus bar or the like, and information from the first circuit block 4 is used to control the second circuit block 6. is operated, and the first circuit block 4 is configured to operate based on information from the second circuit block 6. In the figure, D ₁ , D ₂ , and R ₁ are diodes and resistors connected to the battery 2, and R ₅ and D ₅ are the output terminals of the first circuit block 4 and the first stabilizing current circuit 3.
These are the resistor and diode connected between the emitter of transistor _Q1 that constitutes Q1.

In the above embodiment, the first stabilized power supply circuit 3
A voltage from the battery 2 or the external power supply terminal 1 is constantly applied to the terminal. Therefore, the first stabilized power supply circuit 3 is always in operation, and its output is applied to the first circuit block 4. In a steady state, a high level output appears at the output terminal of the first circuit block 4, and the transistor _Q3 constituting the second stabilized power supply circuit 5 is in an off state. Therefore, the second stabilized power supply circuit 5 is in an inactive state, and the second circuit block 6 is also in an inactive state.

Now, suppose that the output at the output terminal A of the first circuit block 4 becomes low level due to the operation of the timer circuit or the operation of the keyboard constituting the first circuit block 4, the above output is caused by the transistor _Q3 .
is applied to the base of the transistor Q ₃ ,
Q ₅ and Q ₄ are sequentially activated, and the second stabilized power supply circuit 5 is activated. Therefore, in this state, a predetermined voltage is applied to the second circuit block 6, so that the second circuit block 6 operates and the first
Information from the timer and keyboard in the circuit block 4 is subjected to signal processing. Based on the result of the signal processing, the CMOS, RAM, and other circuits in the first circuit block 4 are controlled, and information is exchanged between the first and second circuit blocks 4 and 6. It will be.

By the way, when information is exchanged in this manner, the current flowing through the first circuit block 4 becomes considerably larger than in the steady state. Therefore,
The first stabilized power supply circuit 3 that supplies current to the first circuit block 4 must also be designed to have a capacity sufficient to supply this current.

By the way, if the design were simply designed in this way, a considerably large current would flow through the emitter of the transistor _Q2 that constitutes the first stabilized power supply circuit 3 even in a steady state, which is extremely inconvenient in terms of power saving. be. Therefore, in this embodiment, a fairly large resistor _R4 is connected to the emitter of transistor _Q2 to considerably limit the emitter current in a steady state, and the current flows to the emitter of transistor _Q2 only when information is exchanged. A series circuit consisting of a resistor R ₅ and a diode D ₅ is connected between the emitter of the transistor Q ₂ and the output terminal A of the first circuit block 4 so that the current increases.

That is, in a steady state where no information is exchanged, the output at the output terminal A of the circuit block 4 is at a high level, so the current flowing through the transistor _Q2 is determined by the resistor _R4 and is relatively low. Although this value is small, when information is exchanged and the output at output terminal A of circuit block 4 becomes low level, the transistor
The emitter current of Q ₂ is pulled to the above-mentioned low level, and the current flowing to the emitter of transistor Q ₂ increases only at this time.

As described above, according to the embodiment described above, it is possible to operate the stabilized power supply circuit only when necessary or increase its capacity, and the power consumption by the stabilized power supply circuit can be extremely reduced.

As is clear from the examples above, the power supply device of the present invention has a first
A stabilized power supply circuit for the first circuit block and a stabilized power supply circuit for the second circuit block, which needs to be activated only when necessary, are separately formed.
The stabilized power supply circuit for the second circuit block is controlled to be turned on and off by the output of the circuit block, and the second circuit block is brought into operation, and the connection between the second circuit block and the first circuit block is controlled. It is configured so that when the exchange of signals, information, etc. starts, the current capacity of the stabilized power supply circuit for the first circuit block is automatically increased by the output of the first circuit block. In this state, the power consumption by the stabilized power supply circuit is extremely low, and the stabilized power supply circuit operates only when necessary, and its capacity increases, so it is extremely advantageous in terms of power consumption as a whole and saves power. It has the advantage of making a significant contribution.

[Brief explanation of the drawing]

The figure is a circuit diagram of an embodiment of the power supply device of the present invention. 1...External power supply terminal, 2...Battery, 3...First
stabilized power supply circuit, 4...first circuit block,
5... Second stabilized power supply circuit, 6... Second circuit block.

Claims (1)

[Claims] 1 Separately form a stabilized power supply circuit for the first circuit block, which requires constant power supply, and a stabilized power supply circuit for the second circuit block, which only needs to operate when necessary. , the stabilized power supply circuit for the second circuit block is controlled to be turned on and off by the output of the first circuit block, and the second circuit block is in an operating state and is connected to the first circuit block. When signals and information are exchanged between the two, the output of the first circuit block is used to automatically increase the current capacity of the stabilized power supply circuit for the first circuit block. power supply.