JPH03100479A - Storage battery checking circuit - Google Patents

Abstract

PURPOSE:To estimate the residual capacity of storage battery by stopping the charge making the discharging rate constant at the checking time and checking a specific terminal voltage inherent in the storage battery. CONSTITUTION:By an operation of switch 5 for the checking at the time when the storage battery 1 is being charged by a power supply 4 for charging through a charge circuit 3, a resistor 6 for correction is connected in parallel to a load 2 and a voltage generated in the resistor 6 is applied to a control circuit 7, and the supply of charging voltage to the storage battery 1 from the circuit 3 is interrupted by the circuit 7. At this time, a discharge current becomes to a specified value by the resistor 6 for correction, and the interference of charge voltage to the terminal voltage of the storage battery is isolated, then the specific terminal voltage at the specified loading rate is generated in the storage battery 1 and applied to display circuits 8, 9. When the terminal voltage of the storage battery 1 reaches a discharge finish voltage settled in the circuit 8, a voltage detecting circuit 11 is exerted to turn off a pilot lamp 12, thereby a requirement to start the charge is indicated. When the voltage corresponding to the fully charged state is set to the circuit 9, the enough residual capacity can be indicated by the lighting of pilot lamp 12 of the circuit 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a storage battery inspection circuit for checking the operation of a storage battery that is being charged and discharged, for example, and particularly to checking the state of charge of a storage battery during charging.

[Prior Art] Fig. 3 is a block diagram showing, for example, a conventional storage battery inspection circuit, in which 1 is a storage battery where charging and discharging are performed, 2 is a load of the storage battery, 3 is a charging circuit that charges the storage battery 1, and 4 is a charging circuit for charging the storage battery 1. A charging power source used in the charging circuit 3; 8 a first display circuit indicating that the terminal voltage of the storage battery 1 is in the first range; 8, the storage battery 1;
a second display circuit indicating that the terminal voltage is in a second range;
10 is a setting device, 11 is a voltage detection circuit that compares the voltage at one terminal of the storage battery and the setting value of the setting device 10, and 12 is a display device.

A conventional storage battery inspection circuit is configured as described above, and the storage battery 1 used as a working power source for high-powered machinery is frequently charged and discharged, and the storage battery 1 is inspected prior to work. Although the storage battery 1 is always connected to a load and discharged, a charging power source 4 is connected to the storage battery 1 via a charging circuit 3, and the storage battery 1 is charged by power supply from the charging power source 4. The terminal voltage of the storage battery 1 and the setting value of the setting device 10 are constantly compared, and when the terminal voltage exceeds the setting value, the corresponding indicator 12 lights up. A circuit is provided.

When the storage battery 1 is used for a long time and its terminal voltage reaches near the discharge end voltage indicating the lower limit of the storage battery 1, for example, the indicator 12 of the first display circuit turns off and the storage battery 1 is switched off from the charging circuit 3 before use. A request to charge will be displayed.

In addition, when the voltage at one terminal of the storage battery is sufficient to operate the machinery involved in the work, for example, the indicator light 12 of the second indicator circuit
lights up, indicating that the storage battery 1 can be used without being charged.

[Problems to be Solved by the Invention] In the conventional storage battery inspection circuit as described above, the terminal voltage of the storage battery 1 being charged is influenced by the charging voltage from the charging circuit 3, and the terminal voltage unique to the storage battery 1 is changed. different from. Since the accurate terminal voltage of the storage battery 1 cannot be determined, charging of the storage battery 1 must be temporarily stopped in order to obtain an accurate terminal voltage.

Furthermore, since the voltage at one terminal of the storage battery varies depending on the load condition, that is, the discharge current, the discharge rate cannot be kept constant and the correct terminal voltage cannot be obtained.

Therefore, since the discharge cutoff voltage corresponding to the discharge current of the storage battery 1, that is, the remaining capacity until reaching the discharge end voltage cannot be accurately estimated, there is a problem that the state of charge of the storage battery 1 cannot be accurately grasped.

This invention was made in order to solve such problems, and it is possible to keep the discharge rate of the load constant when inspecting the storage battery 1, and to maintain the terminal voltage unique to the storage battery 1 without being affected by the charging voltage of the charging circuit 3. The purpose is to obtain a storage battery inspection circuit that can accurately grasp the state of charge.

[Means for Solving the Problems] A storage battery inspection circuit according to the present invention includes a switch that commands inspection of the storage battery, and a circuit connected in parallel with the load so that the discharge current from the storage battery becomes a predetermined value during inspection by operating the switch. This system is equipped with a correction resistor connected to the battery, and a control circuit that is activated during inspection by operating the switch and stops charging the storage battery from the charging circuit.

[Operation] In this invention, when the switch is operated to inspect the storage battery, charging from the charging circuit to the storage battery is stopped, and at the same time, a correction resistor is connected in parallel with the load of the storage battery. Therefore, interference of the charging voltage from the charging circuit with the terminal voltage of the storage battery can be isolated, and a terminal voltage unique to the storage battery at a predetermined load factor is always generated in the storage battery.

By checking the terminal voltage of the storage battery using a plurality of voltage detection circuits classified according to the remaining capacity, accurate remaining capacity of the storage battery can be obtained.

Furthermore, by using a momentary type switch for the switch and performing inspection operations in a short period of time, the current consumption of the storage battery by the inspection circuit can be significantly reduced.

Since the remaining capacity is estimated based on the terminal voltage of the storage battery, the state of charge of the storage battery can be accurately grasped, and maintenance of the storage battery such as charging timing can be appropriately performed.

[Embodiment] An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1, 2, 3, 4. Dan, Dan, 10°11.1
2 is the same as the conventional circuit, 5 is a switch operated during inspection, 6 is a correction resistor that adjusts the discharge current so that the load factor of storage battery 1 becomes a predetermined value at inspection, and 7 is a charging circuit during inspection. 3
A control circuit for stopping charging from the battery is shown.

In the storage battery inspection circuit configured as described above, a load 2 is connected to the storage battery 1 terminal and discharge is always performed to the load, and a charging power source 4 is connected via the charging circuit 3. Charging stops when the charging power source 4 is disconnected. When the storage battery 1 is being charged from the charging power source 4 via the charging circuit 3, when the switch 5 is operated to check the storage battery 1, the contact closes. A correction resistor 6 is connected in parallel with the load 2 of the storage battery 1, and the voltage generated across the correction resistor 6 is applied to the control circuit 7. When the control circuit 7 is activated, the supply of charging voltage from the charging circuit 3 to the storage battery 1 is cut off.

That is, charging of the storage battery 1 by the charging circuit 3 is stopped. At this time, the voltage at one terminal of the storage battery is simultaneously applied to the first display circuit and the second display circuit.

Further, when the inspection is completed and the operation of the switch 5 is restored, the contact is opened, and the charging circuit 3 starts charging the storage battery 1 again, and at the same time, the storage battery 1 is discharged only to the load 2. The setting value of the setting device 10 of the first display circuit is set to a value close to the discharge stop voltage at which the storage battery 1 is discharged for a long time and the discharge is stopped. When discharge is performed from storage battery 1 to load 2, Figure 2 shows an example of the charging and discharging characteristics of the storage battery. Immediately after the start of discharge, the terminal voltage drops rapidly, but after that it remains stable for a relatively long period of time, and then returns to the level at the end of discharge. A sudden voltage drop occurs. When the storage battery 1 terminal voltage reaches the discharge end voltage set in the setting device 10 of the first indicator, the voltage detection circuit 11 is activated and the indicator light 12 is turned off. This requests that charging be started immediately. On the other hand, the set value of the second display circuit is set, for example, to the value of the terminal voltage at which the storage battery 1 operates the load 2 and is in a sufficiently charged state. When the indicator light 12 of the second display circuit lights up, it indicates that the storage battery 1 can supply power to the load 2 without being charged and has sufficient remaining capacity.

If the number of installed display circuits is further increased and the setting value of the setting device 10 is set to the corresponding terminal voltage according to the classification of remaining capacity, the accurate terminal voltage of the storage battery 1 at the time of inspection can be determined by the indicator light 12 of the corresponding display circuit. The remaining capacity can be estimated correctly by lighting up.

In the above inspection, the storage battery 1 is isolated from the interference of the charging voltage of the charging circuit 3, and the load factor of the storage battery 1 can always be kept constant, so that the inspection can be performed based on the accurate terminal voltage of the storage battery 1. Therefore, the remaining capacity until the terminal voltage of the storage battery 1 reaches the end-of-discharge voltage and charging is started is estimated, and since the state of charge can be accurately grasped, maintenance of the storage battery 1 such as charging timing can be performed appropriately.

If a momentary type switch is used as the switch 5,
When inspection is not performed, the contact is open and no current is applied to the correction resistor 6, so that current consumption can be reduced.

The present invention can be used for checking the storage battery 1 when charging is performed frequently as necessary by constantly attaching a charging circuit 3 to the storage battery 1 used as a working power source for machinery with large power.

[Effects of the Invention] As explained above, the present invention has a simple structure in which when the switch is operated, a correction resistor is connected in parallel with the load of the storage battery, and at the same time a control circuit that stops charging from the charging circuit is activated. At the time of inspection, discharge from the storage battery is simultaneously performed to the load and the correction resistor, so that the discharge rate can be kept constant, and charging to the storage battery is stopped, so that a terminal voltage unique to the storage battery can be obtained.

Therefore, regardless of charging, the remaining capacity can be estimated based on the correct terminal voltage of the storage battery, and the state of charge can be accurately grasped. As a result, the storage battery can be properly maintained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an example of charging/discharging characteristics of a storage battery, and FIG. 3 is a block diagram of a conventional storage battery inspection circuit. In the figure, 1 is a storage battery, 2 is a load, 3 is a charging circuit, and 4
is a charging power supply, 5 is a switch, 6 is a correction resistor, 7 is a control circuit, 1 is a first display circuit, 9 is a second display circuit, 10 is a setting device, 11 is a voltage detection circuit, 12 is a display I'll go. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) In a storage battery inspection circuit that checks the terminal voltage of a storage battery that receives charge from the charging circuit and discharges to a load, there is a switch that commands inspection of the storage battery, and a switch that commands inspection of the storage battery, and a a correction resistor connected in parallel with the load so that the discharge current of the battery becomes a predetermined value; and a control circuit that is activated during inspection by operating the switch to stop charging the battery from the charging circuit. A storage battery inspection circuit characterized by inspecting the terminal voltage of. (2) The storage battery inspection circuit according to claim 1, wherein the switch is a momentary type that operates only during inspection by operation.