Battery cell voltage and impedance measuring circuit
First Claim
1. A circuit for measuring post voltage and internal impedance value of storage battery cells, the circuit comprising:
- a differential amplifier having inputs connected to battery terminals (+, −
);
a reference constant voltage circuit connected to offset terminals of the differential amplifier;
a direct current coupling circuit connected to an output of the differential amplifier;
a band pass filter configured to allow only signals having a frequency band near to internal impedance voltage signals to be passed;
a A/D converter for converting analog signals into digital signals, wherein the analog signals include alternating current signals flowing into the battery cells, internal impedance voltage signals obtained from an output of the direct current coupling circuit, and direct current voltage of the battery cells obtained from the output of the differential amplifier; and
a central processing unit (CPU) configured to compute internal impedance values by obtaining output signals of the A/D converter.
1 Assignment
0 Petitions
Accused Products
Abstract
In general, in the circuit to measure and diagnose the cell post voltage and internal impedance in storage battery cells and find out their aging status, the impedance voltage signal which is induced by the constant current is added to the direct current voltage on the storage battery cell post. This invention provides a much better method to discriminate the battery cell voltage 1.0 V-12 V and internal impedance voltage from the various noises on the battery cell post voltage like the induced ripple voltage, and then convert them to digital values by means of a A/D converter, and input the digital signals into a CPU. As a result, it raises the degree of accuracy in measurement of the internal impedance value of the battery.
-
Citations
10 Claims
-
1. A circuit for measuring post voltage and internal impedance value of storage battery cells, the circuit comprising:
-
a differential amplifier having inputs connected to battery terminals (+, −
);a reference constant voltage circuit connected to offset terminals of the differential amplifier; a direct current coupling circuit connected to an output of the differential amplifier; a band pass filter configured to allow only signals having a frequency band near to internal impedance voltage signals to be passed; a A/D converter for converting analog signals into digital signals, wherein the analog signals include alternating current signals flowing into the battery cells, internal impedance voltage signals obtained from an output of the direct current coupling circuit, and direct current voltage of the battery cells obtained from the output of the differential amplifier; and a central processing unit (CPU) configured to compute internal impedance values by obtaining output signals of the A/D converter. - View Dependent Claims (2, 3, 4, 6, 9, 10)
-
-
5. A circuit for measuring post voltage and internal impedance voltage storage battery cells, wherein:
-
(i) storage batter cell terminal voltages are connected to non-inverting and inverting input terminals of a high input common mode voltage differential amplifier, negative constant voltages generated by a reference constant voltage circuit are connected to an offset terminal of the differential amplifier, an output of the differential amplifier is converted to A/D values through a DC filter circuit for eliminating noise, and (ii) an output of the differential amplifier is convened into impedance voltage signals after passing a direct current coupling circuit, and then the impedance voltage signals is converted into A/D values after passing through a band pass filter. - View Dependent Claims (7)
-
-
8. A circuit for measuring post voltage and internal impedance value in storage battery cells, wherein:
-
(i) analog signals are connected to multiplexer circuit input channels of an analog to digital converter circuit (ADC), (ii) said analog signals are input to ADC circuit by channel select signals from a CPU output, and (iii) and said analog signals comprise; direct current voltage signals of storage battery cells received as an output of a high input common mode voltage differential amplifier; internal impedance voltage signals obtained from a direct current coupling circuit connected to the output of the high input common mode voltage differential amplifier; and alternating current signals flowing into the storage battery cells.
-
Specification