JPS6021804Y2 - Storage battery discharge state detection device - Google Patents

Description

[Detailed description of the invention] When using a storage battery by alternately charging and discharging it, it is necessary to know the discharge state of the battery.

A discharge meter that measures and displays the discharge state of a storage battery consists of a detection section and a display section.

The former detects the discharge state of the battery, calculates or converts the detected amount, and sends an appropriate output to a display, while the latter receives the output and displays the necessary information.

The present invention relates to the output end of this detection section.

The display section of a discharge meter is not necessarily integrated with the detection section, and moreover, it is often composed of a resistance measurement circuit that is operated by a power source different from that of the detection section, which is powered by the battery under test.

This is because when the battery under test is used as the power source for the display section, the voltage of the battery under test must be lowered in order to obtain the voltage necessary for the display section, and as a result, power is consumed and heat is generated in the part where the voltage drops. This is because the countermeasures become a problem.

In addition, if the power source for the display section is taken out from the middle of the battery under test, excess discharge current will flow through the battery to which the display section is connected, creating a difference in the discharge state between it and other batteries. This is because it causes problems.

As mentioned above, if the display section is a resistance measurement circuit operated by a power source different from the detection section, which is powered by the battery under test, the output terminal of the detection section changes depending on the discharge state of the battery under test. The resistance value must be obtained.

The output terminal of this detection section is connected to the input terminal of the display, and since the display section and the detection section are not necessarily at the same ground potential, the output terminal of the detection section and the resistance connected to it are connected to the input terminal of the display. Must be electrically isolated from other parts.

The present invention provides a storage battery discharge state detection device that satisfies the above-mentioned requirements.

That is, the present invention is a discharge meter that includes a detection section that uses a storage battery as a battery to be measured as a power source and detects the discharge state of the storage battery, and a display section that is operated by a power source different from the storage battery.
The output end of the detection section is composed of a group of resistors whose combined resistance value changes stepwise by opening and closing of a series of electromagnetic switches, and the output end of the detection section is composed of a group of resistors whose combined resistance value changes in a stepwise manner by opening and closing a series of electromagnetic switches. The present invention provides a storage battery discharge state detection device characterized in that it is electrically insulated from the input side of a detection section via an electromagnetic switch.

Next, the operating principle of the device according to the present invention will be explained using a concrete example.

In the example of FIG. 1, the detection section first uses the detection and conversion circuit 3 to
The voltage of the battery to be measured 1 and the discharge current of the battery due to the voltage drop of the shutoff 2 are detected, converted to a current-corrected battery voltage indicating the discharge state, and further outputs a pulse signal corresponding to the voltage.

This pulse signal is counted by the number of pulses in the counting circuit 4 of the detection section, and a binary output corresponding to the number is outputted.

In the output section, as shown in Figure 1, a group of relays (Ry1 to Ryn) connected in parallel to the resistors are connected to binary outputs 2) to 2.
It is driven by n-1 and turned 0N-OFF to change the overall resistance value stepwise at R intervals in the range from R to (2''-1)H.

In addition, the output terminal is connected to the parallel resistor ON and OFF as shown in Figure 2.
There is also a method of changing stepwise in a range n-1 from R to (±)R.

When this device 10 is combined with a resistance measuring type display meter 11 used for an automobile fuel tank, it is connected as shown in FIG. It is used by connecting as shown.

Next, a circuit example of the detection section and the output section is shown in FIG. 5, and the operation of the circuit will be explained.

In FIG. 5, the detection section includes a power supply circuit, a detection and calculation circuit,
Consists of a memory circuit and a counting circuit.

The detection and calculation circuit is composed of IC□ and IC2.

There, the battery voltage and the voltage drop caused by the shunt 2 are added together, and the output is sent to the next stage memory circuit.

The memory circuit is composed of IC3, IC4, IC5 and P field.

IC3 is a voltage follower, IC4 is a comparator, and IC5 is a binary counter (binary output).

IC5 is also the counting circuit 4 of FIG.

The output of IC5 changes at a binary logic level (high level: ground = OV, low level: V) as shown in Figure 6, so when a pulse signal is input to IC5, the resistor Ro-Rn-1 becomes a diode. It can be connected to ground through or connected to -.

As a result, the parallel threat resistance R composed of the resistances Ro to Rn-1 increases in stages until R=111.

The voltage at the dividing point between Rr and the combined resistance R is the value obtained by subtracting the diode voltage drop Vo from the power supply voltage (-(V-V
The partial pressure of D)) is −(V−VD)Xr R+Rr.

This value becomes a reference voltage, which is applied to the comparator IC of the memory circuit and compared with the output of the arithmetic circuit.

When the absolute value of the output of the arithmetic circuit becomes smaller than the absolute value of the reference voltage, the output of IC4 becomes high level and charges the capacitor C.

When the voltage of capacitor C exceeds a certain level, PUT is turned on and a pulse signal is input to binary counter C5.

Then, the output of IC3 changes, the resistance R changes by one step, and the absolute value of the reference voltage becomes smaller and becomes new.

In the output section, the base of the transistor Tro"-Tr (n 1 ) is connected to each output 2° to 2n-1 of IC6,
The output of IC5 causes transistors Tro to Tr(n-
The connection between the collector and base of 1) is turned ON and OFF, and then the relay is turned ON and OFF by turning ON and OFF.

The above is the explanation of the circuit.

As described above, in the storage battery discharge state detection device of the present invention, a resistance value that changes depending on the discharge state of the battery under test is obtained from the output section of the detection section, and a power source separate from the battery under test is used as the power source for the display section. Even when using this method, the power source of the display section and the battery to be measured are electrically insulated, so there are no problems such as leakage between the two, which has excellent advantages.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an example of a device according to the present invention. Figure 2 is an example of a case in which the output end is a combination of parallel resistances, Figure 3 is an example of a combination of a resistance measurement type display meter of an automobile fuel gauge and the device according to the present invention, and Figure 4 is an example of a case in which a constant voltage power supply and an ammeter are used in combination. An example of a case where a display is obtained by connecting the device in series to the output end of the device according to the invention, FIG. 5 shows an example of the circuit of the device according to the invention, and FIG. 6 shows the relationship between the input and output of the counting circuit. 1...Battery to be measured, 2...Shunt,
3...Detection and conversion circuit, 4...Counting circuit, 5, 5'...Output terminal, 10...
Device of the present invention, 11...Display meter, A...
Ammeter, Ry□~Ryn...Relay, R...
···resistance.

Claims (1)

[Scope of utility model registration request] A discharge meter comprising a detection section that uses a storage battery as a battery to be measured as a power source and detects the discharge state of the storage battery, and a display section that is operated by a power source different from the storage battery, and the output end of the detection section is connected to a The output terminal of the detecting section is composed of a group of resistors whose combined resistance value changes stepwise by opening and closing of the electromagnetic switches. A storage battery discharge state detection device characterized by being electrically insulated from the side.