JP2535935Y2 - Power control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] By using a plurality of batteries connected according to the actual voltage of the batteries, the batteries can be used efficiently.

[Industrial applications]

In a device that uses a non-rechargeable dry battery as a power source, the life of the battery determines the usable time of the device.

The present invention satisfies this need and relates to a power supply control circuit that uses a plurality of batteries connected in series.

[Conventional technology]

Dry batteries have a large difference between the discharge start voltage (about 1.6 V) and the discharge end voltage (1.0 V). decide. In such a case, since the battery voltage is higher as the time is closer to the start of discharging, it is necessary to adjust the voltage to a voltage required by the constant voltage power supply circuit (many ICs) before outputting.

For example, when outputting a regulated voltage of 5 V from a constant-voltage power supply circuit, conventionally, six dry batteries rated at 1.5 V are connected in series, connected to the input side of the constant-voltage power supply circuit, and all batteries are connected. Even when the discharge end voltage reaches 1.0 V, a total voltage of 1 V x 6 = 6 V can be input.

[Problems to be solved by the invention]

However, the voltage at which six dry cells are connected in series is much higher than 6 V at the start of discharge (for example, 1.6 × 6 =
9.6V) The constant-voltage power supply circuit that uses this as an input voltage and outputs a regulated voltage of 5V consumes a lot of power as heat inside the circuit. There is a problem you need.

In addition, since a plurality of batteries are connected in series, there is a risk that a new battery and an old battery may be used by mistake for one device at the same time. There is.

 The present invention solves such a problem.

[Means for solving the problem]

In order to solve the above problems, the present invention provides a connecting means for selectively combining a plurality of batteries in series according to a connection control signal, and a voltage in a state where the plurality of batteries are selectively combined and connected in series. And a connection control means for selecting an appropriate combination of the batteries based on the measured voltage measured by the voltage measurement means and outputting the connection control signal to the connection means. And

[Action]

The voltage measuring means measures the voltage of the battery in a state of being selectively combined and connected in series, and supplies the measurement result to the connection control means. The connection control means selects an appropriate voltage from the measurement result, and outputs a connection control signal to the connection means so as to provide a combination of batteries corresponding to the selected voltage. Then, the connection means connects the batteries in series based on the input connection control signal, and as a result, an appropriate voltage is output.

[Example of the invention]

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First
FIG. 2 is a block diagram showing an embodiment of the present invention.

The power supply control circuit 1 includes a microcomputer (hereinafter, referred to as a microcomputer) 10 for controlling each unit, and switches 21 to 23 for switching connection states of batteries 11 to 13 which are exchangeably mounted.
And switches 30, 40, a constant voltage circuit 50 for stabilizing a voltage applied through the switch 30, and an analog / digital converter (hereinafter, A / D converter) for converting the voltage of the switch 30 into voltage data.
D converter) 60.

The microcomputer 10 outputs switching signals from the ports P1 to P5 in order to control the states of the switches 21 to 23 and the switches 30 and 40 based on the voltage data from the A / D converter 60. The operating voltage of the microcomputer 10 is supplied from a control battery (not shown). The operating voltage of the microcomputer 10 is
You may make it supply from 13.

The switches 21 to 23 are respectively provided between the negative electrode of the battery 11 and the positive electrode of the battery 12, between the negative electrode of the battery 11 and the positive electrode of the battery 13, and between the negative electrode of the battery 12 and the positive electrode of the battery 13. These switches 21 to 23 are on / off controlled by switching signals output from ports P1 to P3 of the microcomputer 10.

The switch 30 includes individual contacts 31 to 33 and a common contact 34, and the positive contacts of the batteries 11 to 13 are connected to the individual contacts 31 to 33, respectively. Also, the switch 40 has individual contacts 41 to
The individual contacts 41 to 43 are connected to the negative electrodes of the batteries 11 to 13, respectively. The common contact 34 of the switch 30 is connected to the constant voltage power supply circuit 50, and the common contact 44 of the switch 40 is grounded. The common contact 34 of the switch 30 is connected to the A / D converter 60. These switches 21 to 23, 30, and 40 are ports of the microcomputer 10.
The connection state is controlled by the switching signals from P1 to P5. And these form a series connection means.

Here, the connection operation of the batteries 11 to 13 by the switches 21 to 23, 30, and 40 will be briefly described. The microcomputer 10 is a switch 21
23, the batteries are selectively connected, the positive electrode of the selected battery is selected by the switch 30 and connected to the constant voltage power supply circuit 50, and the negative electrode of the selected battery is connected to the switch 40.
To select and ground.

 Table 1 shows the selected batteries and the state of each switch.

However, the numbers corresponding to the switches 30 and 40 in Table 1 indicate the individual contacts connected to the common contacts 34 and 44.

The constant voltage power supply circuit 50 keeps the voltage between the common contact 34 and the ground constant, and outputs the constant voltage (for example, 1.5 V) to a terminal 71 to which a device (not shown) is connected. The input voltage required for making the output voltage constant in the constant voltage power supply circuit 50 is a voltage higher than the constant voltage by a predetermined voltage (for example, 2.5 V). The capacitor C is for smoothing the voltage output from the constant voltage power supply circuit 50, and need not be provided if the output voltage of the constant voltage power supply circuit 50 is sufficiently smoothed.

Next, the operation of this embodiment will be described. Figure 2 shows the microcomputer 10
6 is a flowchart showing the operation of the first embodiment.

First, the process proceeds to step S1, where a connection signal is output from the ports P1 to P5, and the batteries 11 and 12 are operated by the switches 21 to 23, 30, and 40.
Connect. Then, the process proceeds to step S2 to determine whether the voltage data given from the A / D converter 60 is equal to or more than the value corresponding to 2.5 V.
If it is less than 2.5 V, the process proceeds to step S6 to switch to another combination of batteries.

In step S3, the combination of batteries is kept for a predetermined time (for example, 30
Start the timer to switch every second)
Move to S4, determine whether the voltage data is 2.5V or more, if the voltage data is 2.5V or more, move to step S5,
If the voltage data is less than 2.5 V, the process proceeds to step S6 to switch to another battery combination. In step S5, it is determined whether or not the timer started in step S3 has expired. If the timer has ended, the process proceeds to step S6, and if not, the process proceeds to step S4 to monitor the voltage data again.

In step S6, the voltage data from the A / D converter 60 is stored in the voltage data storage area A corresponding to the combination of the batteries 11 and 12, and the process proceeds to step S7.

In step S7, batteries 12 and 13 are connected, and the process proceeds to step S8. In steps S8 to S11, steps S2 to S5
Similarly to the above, if the voltage data from the A / D converter 60 is 2.5 V or more, the process proceeds to Step S12 after the elapse of the predetermined time.
Move to step S12. In step S12, the A / D converter 6 is stored in the storage area B of the voltage data corresponding to the combination of the batteries 12 and 13.
The voltage data from 0 is stored, and the routine goes to Step S13.

In step S13, batteries 11 and 13 are connected and step S14
Move to In steps S14 to S17, as in steps S2 to S5
If the voltage data from the A / D converter 60 is 2.5 V or more, the process proceeds to step S18 after the elapse of a predetermined time, while the voltage data is
If the voltage drops below 2.5V, even if the specified time has not elapsed, the step
Move to S18. In step S18, the voltage data from the A / D converter 60 is stored in the voltage data storage area C corresponding to the combination of the batteries 11 and 13.

As described above, the voltage data corresponding to all the combinations of the two batteries are stored in the storage areas A, B, and C by steps S1 to S18, and the initialization of the storage areas A, B, and C is completed.

Then, proceeding to step S19, the voltage data stored in the storage areas A, B, C are compared, two batteries corresponding to the largest voltage data among them are connected, and then proceed to step S20. In step S20, the voltage data from the A / D converter 21
It is determined whether the voltage is equal to or higher than 2.5 V. If the voltage is equal to or higher than 2.5 V, the process proceeds to step S22 to start the timer, and then proceeds to step S23. On the other hand, if it is determined in step S21 that the voltage is less than 2.5 V, even if two batteries are connected, the series voltage is 2.
It is determined that the voltage does not exceed 5 V, and the process proceeds to step S26.

In step S23, the voltage data from the A / D converter 60 is 2.5V
It is determined whether the voltage is equal to or more than 2.5 V.
The process proceeds to step S25 if the voltage is less than 2.5 V. In step S24, it is determined whether the timer has expired. If the timer has not expired, monitoring of the voltage data is performed in step S23. If it is determined in step S24 that the timer has expired, the process proceeds to step S25. In step S25, the voltage data from the A / D converter 60 is stored in an area corresponding to the battery combination selected in step S20, and the voltage data is updated. Then, the process proceeds to step S19, and the operations in steps S19 to S25 are repeated until the voltage data from the A / D converter 60 becomes less than 2.5V.

Then, when it is determined in step S21 that the voltage data is less than 2.5 V and the process proceeds to step S26, all three batteries 11 to 13 are connected, and the process proceeds to step S27. Then, the step S27 is repeated while the voltage data from the A / D converter 60 is 2.5 V or more, and when the voltage data becomes less than 2.5 V, a warning is issued to the effect that the voltage has dropped (step S28), and the process ends.

Therefore, in this embodiment, the combination of two batteries is used first so that the input voltage is equal to or higher than the minimum input voltage in the constant voltage power supply circuit 50. When the input voltage cannot be obtained, the voltage is supplied to the constant voltage power supply circuit 50 by three batteries, so that the voltage drop in the constant voltage power supply circuit 50 can be reduced, and the batteries can be used efficiently. be able to.

In addition, since the power is supplied to the device by connecting the combination having the highest voltage among the combinations of the two batteries first, the battery that generates the highest voltage (that is, the degree of consumption is low) is mainly used. And the three batteries have the same amount of power,
That is, since the voltage generated for each battery becomes equal,
There is an advantage that liquid leakage due to the generated voltage variation is unlikely to occur.

Note that the above embodiment measures the series voltage of a plurality of batteries,
Although the connection of the batteries is switched based on the measurement result, for example, the voltage of each battery may be measured, and the connection of the batteries may be switched based on the measurement result.

[Effect of the invention]

As described above in detail, according to the present invention, since a plurality of batteries are connected and used according to the voltage generated from the batteries, the number of batteries is selected and connected so that the required voltage is obtained. And the battery can be used efficiently.

Further, since the battery can be used in accordance with the degree of consumption of the battery, it is possible to selectively use the battery so as to reduce variation in the voltage of the battery, thereby preventing trouble such as liquid leakage. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of the microcomputer 10. In the figure, 1: power supply control circuit, 10: microcomputer, 21 to 23, 30, 40: switch, 50: constant voltage power supply circuit, 60: A / D converter.

Claims (1)

(57) [Scope of request for utility model registration] 1. A connecting means for selectively combining a plurality of batteries in series according to a connection control signal, and a voltage measuring means for measuring a voltage in a state where the plurality of batteries are selectively combined and connected in series. A power supply control circuit comprising: a connection control unit that selects an appropriate combination of the batteries based on the measured voltage measured by the voltage measurement unit and outputs the connection control signal to the connection unit.