JPS5999272A - Decision device of remaining capacity of battery - Google Patents

Abstract

PURPOSE:To applying periodically a voltage to a load while the load is not in operation and to detect the voltage at that time by deciding on whether a battery has the remaining capacity enough to operate the load, and generating an alarm when the load does not has the enough capacity. CONSTITUTION:A detecting circuit 16 detects the voltage applied to a solenoid valve 6 when the solenoid valve 6 is driven for the time when the solenoid valve 6 is not in operation through resistances 17 and 18. Simultaneously, a high signal is received from the output port O3 of a microcomputer 2 to supply the power to a comparator 21 while a reference voltage is produced by a resistance 19 and a diode 20 to compare the voltage applied to the solenoid valve 6 with the reference voltage; when the voltage applied to the solenoid valve 6 is lower than the reference voltage, a high signal is outputted and sent to the input port I1 of the microcomputer 2. Consequently, a decision on the remaining capacity of the battery 1 in the state wherein the load operates is made, and when the capacity is less than the reference level, a pilot lamp is turned on to generate an alarm.

Description

DETAILED DESCRIPTION OF THE INVENTION Page 2 Industrial Application Field The present invention relates to a device for determining the remaining capacity of a battery as a power source for a device having a load that operates after a predetermined period of time has elapsed after voltage application.

The configuration of the conventional example and its problem 1 is a battery as a power source for the device, and 2 is a microcomputer. Reference numeral 3 denotes a drive circuit, which is composed of a transistor 4 and a resistor 5 so as to drive a load when the output port 01 of the microcomputer 2 becomes low. Reference numeral 6 denotes a load that starts operating after a predetermined time has elapsed after voltage application, and is, for example, a solenoid valve.

7 is a detection circuit that constantly compares the voltage of the battery 1 with a reference voltage, outputs the judgment result, and sends it to the input capacitor (X+) of the microcomputer 2, and its configuration includes a resistor 8. Resistance9. Resistance 10. Diode 11. It consists of a comparator 12, resistors 8 and 9 detect a voltage corresponding to the battery voltage, and resistor 1o and diode 11 create a reference voltage. Compare both voltages with a comparator,
If the voltage corresponding to the battery voltage is lower than the reference voltage, it outputs a high 3, -ji signal and inputs the microcomputer 2).
I am sending it to +. When microcomputer 2 receives this high signal, microcomputer 2 outputs port 0.
2 outputs a high signal.

The notification circuit 13 consists of a resistor 14 and an LED 15, and upon receiving the high signal of , lights up the LED at a constant cycle to issue an alarm.

According to the configuration of this conventional example, although deterioration of the battery 1 due to long-term use can be detected, the microcomputer 2
When driving the solenoid valve 6 in response to a signal from the output port of
A considerable amount of current flows through the solenoid valve 6, causing a drop in the voltage of the battery 1. Therefore, even though the solenoid valve 6 is driven for a predetermined period of time, and even though the output result of the detection circuit 7 shows that the remaining capacity of the battery 1 is adequate to drive the device, Nevertheless, the solenoid valve 6 may not operate. This takes into consideration the drop in the voltage of battery 1 when current starts flowing through solenoid valve 6, since the voltage of battery 1 is detected by detection circuit 7 when solenoid valve 6 is not operating. This is because it makes it easier to make accurate judgments.

Since the detection circuit 7 is always energized, this detection circuit itself prevents battery consumption.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the prior art as described in (-) above, and aims to reliably notify the remaining capacity of a battery.

Structure of the Invention The present invention determines whether the remaining battery capacity is sufficient to operate the load, and issues an alarm if there is no capacity to operate the load.
The configuration is such that a voltage is applied and the voltage at that time is detected to make a determination.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals. 16 is a detection circuit, which detects the voltage applied to the solenoid valve 6 by a resistor 17 and a resistor 18 when the solenoid valve 6 is driven during the period when the solenoid valve does not operate, and simultaneously detects the output of the microcomputer 2. Port 03
When receiving a high signal from , the resistor 19 and diode 2o create a reference voltage while supplying power to the comparator 21.
These two voltages, that is, the reference voltage and the voltage applied to the solenoid valve 6 are compared by the comparator 21, and if the voltage applied to the solenoid valve 6 is lower than the reference voltage, a high signal is output and the microcomputer 2 It is sent to input boat 1. 22 is a backup circuit, and when the solenoid valve 6 is driven, a considerable current flows through the solenoid valve 6, and if the voltage of the battery 1 decreases, the microcomputer 2 may not be able to receive power to operate normally, so the resistor 23 is connected to the back-up circuit. The battery 1 is backed up using a capacitor 24.

Next, the timing of the operation will be explained with reference to FIG. (A
) is a timing chart of the output port 01 of the microcomputer 2, and the time for driving the solenoid valve 6 is assumed to be effective from tl for determination. The time T is the time required to operate the solenoid valve 6. (B) is microcomputer 2
(C) is a timing chart showing fluctuations in the voltage of battery 1. (D) is a timing chart showing fluctuations in power supply Vnn of microcomputer 2.
(E) is the output of the detection circuit 16 when it is determined that the voltage applied to the solenoid valve 6 is lower than the reference voltage, and (F) is the output of the notification circuit 13 at the time when the notification circuit 13 is delayed by the time t.

This is a timing chart in which LEDlts is displayed and the lighting is repeated at a cycle of (to + tp).

First, the microcomputer 2 periodically switches from a high signal to a low signal at time t1 to drive the drive circuit 3, as shown in FIG. At the same time,
Current flows through the solenoid valve 6, voltage is applied, and the output port 0
As shown in Φ), the low signal changes to a high signal, and the detection circuit 16 operates to create a reference voltage, while supplying power to the comparator to detect and compare the voltage applied to the solenoid valve 6. There is. At this time, the voltage of battery No. 1 decreases as shown in (C) because current flows through the solenoid valve 6. The power supply Vnn of Micro Combi Coater 2 is still (D)
As shown in the figure, there is almost no voltage drop. This 7
The backup circuit 22 guarantees the operation of the microcomputer 2. If the voltage applied to the solenoid valve 6 is lower than the reference voltage, the detection circuit 16 outputs a high output as shown in Φ). The micro combi coater 2 receives this output from the input 11 immediately before the time when the first drive of the solenoid valve 6 is stopped, and after a delay of time tD, it receives the output from the input 11.
Turn on D15 (blink periodically at the timing shown in Fl to issue an alarm).

In this way, according to this embodiment, the remaining capacity of the battery 1 when the load is actually operating can be determined, and if the voltage is below the reference voltage, the indicator light is turned on to issue a warning, and the remaining capacity of the battery 1 when the load is not operating can be determined. This has the effect of being able to notify you of the remaining capacity.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Determining the remaining battery capacity by taking into account the drop in battery voltage caused by passing current through the load, that is, determining the remaining battery capacity in the circuit state where the load is actually operating, and if the load is operating. An alarm will be issued if the remaining battery capacity is insufficient.

(2)) Since the determination is made periodically and the detection circuit is energized only when the determination is made, battery consumption during the determination can be reduced.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing a conventional battery remaining capacity determination device;
The figure is a circuit diagram showing a battery remaining capacity determination device according to an embodiment of the present invention, and FIGS. 3(A) to 3(F) are timing charts for determining the battery remaining capacity in FIG. 2. 1...Battery, 2...Microcomputer, 3...Drive circuit, 6...Load,
13...Notification circuit, 16...Detection circuit. Name of agent: Patent attorney Toshio Nakao and one other person (Ω

Claims (1)

[Claims] A microcomputer, a drive circuit that drives a load in response to a signal from the microcomputer, a load that is driven by the drive circuit and starts operating after a predetermined period of time has elapsed from the start of driving, and a drive circuit that receives a signal from the microcomputer and starts operating after a predetermined period of time has elapsed from the start of driving. A detection circuit that compares the reference voltage with the voltage applied to the load and outputs the judgment result and sends it to a microcomputer, an alarm circuit that receives a signal from the microcomputer and issues an alarm, and a battery that serves as a power source for the device. The microcomputer periodically drives the drive circuit for a time shorter than the predetermined time, and
A battery remaining capacity determination device that drives the notification circuit when the output of the determination result of the detection circuit at that time is an output indicating that the voltage applied to the load is lower than the reference voltage.