SU716091A1 - Device for measuring storage battery internal resistance - Google Patents

Description

one

The invention relates to the electrical industry, in particular with regard to monitoring the parameters of chemical current sources.

Devices are known for measuring the internal impedance of a battery on a pulsed current, containing a power switch, a switching battery load current, storage capacitors, and their switching keys and measuring device 1 and 2.

The disadvantage of these devices is that the pulses transmitted through the battery current are not stabilized, in addition, the devices have low sensitivity.

Known are also devices containing a master oscillator, a generator of stabilized current pulses, a key element, a measuring amplifier, and a mean voltmeter 3.

A disadvantage of such devices is the occurrence of additional error with increasing frequency of the modulation current. Moreover, the magnitude of this error for different batteries is different. With

Claims (3)

careful oscillography of the voltage on the battery Against the background of right-angle pulses of the useful signal, inductive surges (pulses) were detected. The battery replacement circuit contains inductance. When a rectangular current pulse with a frequency of 1 kHz is passed through the inductance, voltage spikes occur on it, which are much higher than the voltage drop across the active component of the internal resistance. Inductive, bursts and introduce significant errors in the readings of the instrument prototype. The error introduced by the inductive surge depends on the inductance of the battery and the type of voltmeter at the output of the measuring amplifier. When using a peak voltmeter, the error reaches 100–300%, and when using a voltmeter, an average value of 15–20 ° / o. It is preferable to use a peak voltmeter, since its sensitivity is 2 times the sensitivity of the average voltmeter. Sensitivity is of great importance, since when pulses are passed through an accumulator of the order of units of amperes, the measured voltage is low (ImV - lOOmV). Thus, the disadvantage of the prototype device is that it is sensitive to parasitic inductive voltage spikes on the battery, which causes an additional error. The purpose of the invention is to improve the accuracy and sensitivity when measuring the internal resistance of a battery. This is achieved in that inductive voltage spikes are suppressed by a key element connected between the battery and the measuring amplifier. The key element is controlled by the locking pulse driver, which is synchronized by the master oscillator. An increase in sensitivity is achieved using a peak voltmeter. FIG. 1 shows a block diagram of a device for measuring the internal resistance of a battery; in fig. Figure 2 shows the diagrams of stresses arising from the operation of the device. The device consists of a generator 1 of stabilized current pulses, the output of which is connected to the terminals of a controlled battery 2. The generator 1 is controlled by a master generator of 3 pulses. Between the battery 2 and the measuring amplifier 4, the locking key 5 is connected. The control input of the key 5 is connected to the output of the locking pulses 6, the input of which is connected to the output of the master oscillator 3. A peak voltmeter 7 is connected to the output of the measuring amplifier. The current pulses (curve a) from the output of the generator I, the passage through the internal resistance of the battery 2, causes the appearance of voltage pulses on the last (curve b). As can be seen from the diagram, the voltage pulses on the battery 2 contain inductive voltage surges. Shaper b gives the locking pulses (curve c). The locking pulses arrive at the control input of the locking key 5 connected between the battery 2 and the measuring amplifier 4. As a result, the locking key 5 does not transmit inductive voltage surges to the input of the measuring amplifier 4 (curve r). The generator of stabilized current pulses is made in the form of a constant-current stabilizer locked by pulses of the reference generator. The master oscillator is designed as a multivibrator. A field-effect transistor is used as a locking key. Shaper pulse shaper represents a waiting multivibrator with a pulse duration of 3 to 10 times less than the duration of the pulses of the master oscillator. The technical effect created by the invention is to increase the measurement accuracy by 15-20% and to increase the sensitivity of the device by 2 times, i.e., to reduce the error in the diagnosis of the technical condition of the battery. The increase in measurement accuracy in the proposed device is due to the use of a locking key that does not allow interference in the form of an inductive voltage surge to the input of the measuring amplifier. The increase in sensitivity is achieved through the use of a peak voltmeter. Claims An apparatus for measuring the internal resistance of a battery, comprising two output terminals, a master oscillator, one output of which O is connected to a generator of stabilized current pulses, a measuring amplifier connected to a voltmeter, and a key element, characterized in that, in order to increase accuracy and sensitivity, a shaper pulse former is introduced into it, the output of which is connected to the control input of a key element connected between one of the output terminals and the measuring amplifier In this case, the control input of the locking pulse generator is connected to another output of the master oscillator, and a peak voltmeter is used at the output of the measuring amplifier. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 199942, cl. H 01 M 10/48, 1965. 2. USSR author's certificate number 29016, cl. H 01 M 10/48, 1968. 3. The UK patent number 1342294, cl. G1U, 1974. rig i I