JPH053934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for detecting changes in the characteristics of two electronic components of the same type, such that changes in the characteristics of the electronic component can be captured as changes in the amplitude of pulses generated by the electronic component. This relates to a pulse amplitude comparison circuit that corrects the initial deviation of the pulses generated by each electronic component when comparing. For example, it examines the pulse component of the battery terminal voltage that occurs when charging and discharging a secondary battery in a pulsed manner. It is used for things such as.

BACKGROUND ART In recent years, various types of secondary batteries have been used as power sources for power outage compensation, and as the reliability of electronic circuit devices has improved, information regarding the deterioration of secondary battery power sources has become required. Ta. For example, in sealed Ni-Cd batteries, it has been found that there is a strong correlation between battery deterioration and internal resistance. It can be understood as a pulse-like change in voltage. Taking advantage of this characteristic, the secondary battery used is divided into two sets of assembled batteries, and these batteries are commonly charged or discharged in a pulsed manner.
Another method has been proposed for detecting battery deterioration by comparing the pulse components of the terminal voltages of the assembled batteries.

Problems to be Solved by the Invention However, even if the internal resistance of a secondary battery is a normal product without deterioration, there is a considerable deviation, and therefore the initial deviation of the internal resistance, in other words, the terminal voltage of the assembled battery. It is necessary to correct the pulse component of the battery while the battery is normal, and then detect changes due to subsequent deterioration.

However, conventionally, a pulse amplitude comparison circuit suitable for such signal processing has not been provided. The present invention provides a pulse amplitude comparison circuit capable of correcting an initial deviation in the amplitudes of two input pulse signals so as to be suitable for this type of signal processing.

Means for Solving the Problems To achieve this object, the pulse amplitude comparator circuit for correcting the initial deviation of the present invention simultaneously operates a microcomputer and a first control signal supplied from the microcomputer. a comparator to which two input pulses configured to arrive are respectively provided via a capacitor to an input terminal; and means for biasing a common mode voltage provided to one input terminal of said comparator;
Controlled by a second control signal connected to the other input terminal of the comparator via a resistor and having a pulse width from a time preceding the first control signal to the first control signal. A first switching means and a third control signal supplied from the microcomputer alternately keep the common mode voltage at the two input terminals of the comparator constant each time the first control signal is generated. and second switch means for changing only the value.

Effect This configuration allows the microcomputer to
Gradually lowering the voltage at the other input terminal of the comparator through the first switching means in a direction that cancels out the bias voltage applied to the other input terminal, and finding a point where the peaks of the two input pulses coincide. This corrects deviations in pulse amplitude. Next, the second switch means compares the two input pulses while lowering the common mode voltage of the two input terminals by a fixed value alternately, so that one input pulse changes and the above-mentioned fixed value is lowered. It will be detected whether it exceeds the limit.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a pulse amplitude comparison circuit for correcting initial deviation in an embodiment of the present invention. In FIG. 1, 1 and 2 are pulse input sources, respectively, and a first control signal 10 supplied from a microcomputer 10.
0 simultaneously generates a pulse. 3 and 4
are capacitors, respectively, and input sources 1 and 2
The DC component of is cut off, and only the pulse component is supplied to the input terminal of the comparator 9. A biasing means 5 biases the common mode voltage at one input terminal of the comparator 9 by an amount corresponding to the maximum value of initial deviation correction. Reference numeral 6 denotes a first switch means, which biases the common mode voltage at the other input terminal of the comparator 9 by a second control signal 200 in accordance with the correction width of the initial correction. 7 is a second switch means, during the correction of the initial deviation, the supply of the third control signal 300 is stopped, it does not have any effect on the two input terminals of the comparator 9, and the amplitude of the input pulse after correction is changed. In the comparison state, the third control signal 3
00, the common mode voltage of any input terminal of the comparator 9 is lowered by a value corresponding to the permissible limit of the amplitude difference of the pulses to be measured. 8 is a resistor, 9 is a comparator, and 10 is a microcomputer. 100, 200 and 3
00 are first, second and third control signals supplied from the microcomputer 10.

The operation of the pulse amplitude comparison circuit for correcting the initial deviation configured as above will be described below with reference to FIGS. 1 to 3. First, correction of the initial deviation of pulse amplitude will be explained.
FIG. 2 shows the waveforms of the first, second, and third control signals and the input terminal voltage of the comparator 9. In particular, the input terminal voltage waveform of d is easy to understand because the two waveforms overlap. The time axis is shown slightly shifted. First, as shown in c, a, and c, generation of the third control signal supplied from the microcomputer 10 is stopped. In this state, inside the second switch means 7, the switch contact is connected to the bottom. For this reason,
The common code voltage at one input terminal (inverted phase input terminal in FIG. 1) of the comparator 9 is biased in the negative direction by the bias means 5. Therefore, the output of the comparator 9 is "High". A second control signal 200 is then applied to the first switching means 6 as shown in FIG. 2b.
As a result, part of the charge stored in the capacitor 3 is discharged through the resistor 8, etc., and the comparator 9
The voltage at the other input terminal (the positive phase input terminal in FIG. 1) begins to decrease with a gentle slope, as shown in FIG. 2d. After t seconds of generation of the second control signal, the first control signal 100 shown in FIG.
Two input pulses are generated simultaneously and applied to the input terminals of comparator 9 via capacitors 3 and 4, respectively. As a result, the voltage waveforms at the two input terminals become as shown in FIG. 2d. While t is small, the voltage drop at the positive phase input terminal of the comparator 9 caused by the first switching means 6 is small and the output of the comparator 9 remains "High". Repeat the above operation periodically,
When the value of t is increased by a constant value each time an input pulse arrives, the voltage drop at the positive-phase input terminal brought about by the first switching means 6 gradually increases until it reaches d in FIG. As shown by the broken line, the magnitude relationship of the input terminal voltage of the comparator 9 at the time of the arrival of the pulse is reversed.
In this state, the negative phase input terminal of the comparator 9 is supplied with a voltage obtained by adding the input pulse amplitude of the input source 1 to the bias voltage from the bias means 5, while the positive phase input terminal is supplied with a voltage obtained by adding the input pulse amplitude of the input source 1 to the bias voltage from the bias means 5. A voltage obtained by adding the input pulse amplitude of input source 2 to the voltage decrease caused by
It can be said that both are approximately equal. The value of t at this point
By storing t _p in the microcomputer 10 and applying it to the subsequent comparison of the amplitudes of two input pulses, the initial deviation of the amplitudes of the two input pulses can be corrected.

The operation of a comparator circuit that identifies whether a subsequent change in two input pulses is within predetermined tolerance limits will now be described. FIG. 3 shows voltage waveforms similar to those in FIG. 2 in the comparison mode of operation. a third controlling the second switching means 7;
The control signal 300 is composed of two control signals A and C, which turn on contact A and C, respectively, corresponding to switch contacts A and C inside the second switch means 7. As shown in FIG. 3c, they are out of phase with each other. Further, this third control signal is inverted every time an input pulse arrives.

Now, when the switch contact C in the second switch means 7 is turned on by the third control signal C, a constant current flows through the second resistor 11, and the positive phase input terminal of the comparator 9 The common mode voltage decreases by a certain value. The amount of decrease of this constant value is made equal to the value of the permissible limit of the difference between the two input pulse amplitudes. Therefore, immediately after the initial deviation is corrected, the voltage waveforms at the two input terminals of the comparator 9 are as shown on the left side of FIG. smaller than the terminal by the allowable limit value,
The output of comparator 9 becomes "Low". If the amplitude of the input pulse supplied to the negative phase input terminal changes in this state and the amount of change exceeds the permissible limit, the magnitude relationship between the two input terminal voltages of the comparator 9 will be reversed. The output of the comparator 9 becomes "High". As a result of the above, the third
It can be seen that when the control signal C is supplied, the output of the comparator 9 is normal when it is "Low" and abnormal when it is "High".

Next, when the third control signal A is supplied and the switch contact A in the second switch means 7 is turned on, a constant current flows through the third resistor 12 which is equal to the second resistor 11. The common mode voltage at the negative phase input terminal of the comparator 9 decreases by a constant value, and the amount of decrease is equal to the allowable limit of the difference between the two input pulse amplitudes. Therefore, immediately after the initial deviation is corrected, the voltage waveforms at the two input terminals of the comparator 9 are as shown on the right side of FIG. The output of the comparator 9 becomes "High" because it is smaller than the terminal by the allowable limit value.
If the amplitude of the input pulse supplied to the positive phase input terminal changes in this state and the amount of change exceeds the allowable limit, the comparator 9
The magnitude relationship between the two input terminal voltages is reversed, and the output of the comparator 9 becomes "Low". As a result, it can be seen that when the third control signal A is supplied, the output of the comparator 9 is normal when it is "High" and abnormal when it is "Low". Finally, the microcomputer 10 determines the output logic of the comparator 9 in response to the third control signals A and C, and outputs whether the difference in amplitude between the two input pulses is normal or abnormal.

Note that in this embodiment, two input terminals of the comparator 9 are specified for convenience of explanation, but the present invention is not limited to this.

Effects of the Invention As described above, the present invention provides a bias means that supplies two input pulses having different amplitudes to the input terminals of the comparator through capacitors in an initial state, and that is connected to one input terminal of the comparator. After correcting the amplitudes of the two input pulses by a first switching means connected via a resistor to the other input terminal, a second switching means alternately applies a voltage equal to the permissible limit value to the two input terminals of the comparator. By changing the common mode voltage and configuring the comparator to determine the output logic of the comparator,
After correcting the amplitude of two input pulses that have an initial deviation, it is possible to detect the subsequent change in amplitude, for example, when two sets of secondary batteries are charged or discharged at the same time. Deterioration of the battery can be determined by examining the state of pulse-like changes in voltage.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing time charts of various control signals and input terminal voltage waveforms of the comparator when correcting the initial deviation, and FIG. 3 is a diagram showing the input terminal voltage waveform of the comparator. FIG. 7 is a diagram showing time charts of various control signals and input terminal voltage waveforms of a comparator when performing a pulse amplitude comparison operation. 1...Input source, 2...Input source, 3...Capacitor, 4...Capacitor, 5...Bias means, 6
...First switch means, 7...Second switch means, 8...Resistor, 9...Comparator, 10...
...Microcomputer, 11...Second resistor,
12...Third resistance.

Claims (1)

[Claims] 1 a microcomputer; a comparator to which two input pulses configured to arrive simultaneously by a first control signal supplied from the microcomputer are respectively supplied to input terminals via capacitors; and the comparator; means for biasing a common mode voltage supplied to one input terminal of the comparator; a first switching means controlled by a second control signal having a pulse width of , and second switch means for alternately changing the common mode voltage of the two input terminals of the comparator by a fixed value, and the microcomputer comprises:
The generation of the third control signal is stopped, and the common mode voltage is maintained in a state where no change is applied to either of the two input terminals of the comparator, and the pulse width of the second control signal is set to the same value as that of the second control signal. a correction function that sequentially supplies the control signal so as to increase by a constant value each time the control signal is generated, and stores the pulse width of the second control signal when the output of the comparator is inverted; and the third control A signal controls said second switch means to switch two of said comparators.
The initial deviation is characterized by having a pulse amplitude comparison function that alternately changes the common mode voltage of the two input terminals by a fixed value and determines the output logic of the comparator in response to switching of the second switching means. Pulse amplitude comparison circuit that corrects.