SU1651222A1 - Spark energy meter - Google Patents

Abstract

The invention relates to electrical measuring equipment, in particular, to devices for measuring the energy of fast processes, and can be used, for example, to measure the electrical energy of a spark generated in spark plugs. The aim of the invention is to improve the measurement accuracy. This goal is achieved by introducing and appropriately connecting the driver 10 pulse and RS trigger 9 to synchronize the switching times of the integrator and A1Sh with the frequency of the measured discharge pulses, as well as synchronize the reset of the integrator with the end of the measurement of A1Sh. The information at the A1Sh output remains unchanged between the measured bit pulses. 2 Il. i

Description

. 1

The invention relates to electrical measuring equipment, in particular, to devices for measuring the energy of fast-flowing pulsed processes, and can be used to measure the electrical energy of discharge pulses that occur in spark plugs when switched on or off.

(for example, in a semiconductor spark plug). R the instant of the signal at the output of the voltage measuring transducers 1 (Fig. 2a) and the current 2 (Lig. 26) with the appearance of a spark discharge (the discharge current curve has the form of a damped sinusoid), the comparator 7 forms a series of switches in the switching equipment and a device of coal impulses (fig. 2c). Com

a similar value.

The aim of the invention is to improve the measurement accuracy of the device.

FIG. 1 shows the structure on the diagram of the energy meter ncr $ in FIG. 2s are timing diagrams that show his work.

The spark energy meter contains a voltage measuring transducer t, a current measuring transducer 2, a multiplier of 3 signals integrator 4, an analog-to-digital converter (ADC) 5, indicator b, comparator 7, one-shot 8, RS-flip-flop 9, pulse generator 10 analog a switch 11, the outputs of the measuring voltage converters 1 and current 2 are connected to the inputs of the multiplier 3 signals, the output of which is connected to the input of the integrator

4, the output connected to the input of the ADC

5, the output of which is connected to the indicator 6, the input of the comparator 7 is connected to the output of the current measuring converter 2, the output of the comparator 7 is connected to the input of the single vibrator 8 and the installation input of the RS flip-flop 9, the output of the single vibrator 8 is connected to the input of the pulse former 10, the output of which is connected to ADC trigger input

5, the output The last measurement end is connected to the reset input of the RS trigger 9, the output of the RS trigger 9 is connected to the control input of the analog switch 11 connected to the reset circuit of the integrator 4.

The meter works as follows.

The voltage measuring transducer 1, which is, for example, a voltage divider, is connected by its inputs parallel to the investigated spark gap. A measuring current transducer, for example, a measuring current transformer, is connected in series with the spark gap under test. In the spark gap with a certain frequency spark discharges

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(for example, in a semiconductor spark plug). R the instant of the signal at the output of the voltage measuring transducers 1 (Fig. 2a) and the current 2 (Lig. 26) with the appearance of a spark discharge (the discharge current curve has the form of a damped sinusoid) the comparator 7 forms a series of pr 5

0

0

five

five

0

five

0

five

Parator 7 is switched on in such a way that the first rectangular pulse at its output corresponds to the first half-wave of the discharge current. The magnitude of the reference voltage of the comparator 7 is selected corresponding to the transition current of the preparatory discharge stage to a spark in a semiconductor spark plug (Fig. 26). At the same time, on the front of the first pulse at the output of the comparator 7, the RS-flip-flop 9 generates a logical 1 signal at its output (Fig. 2d), which opens the analog key 11 connected to the reset circuit of the integrator 4. The output signal of the multiplier 3 is about the instantaneous power sparks, is fed to the input of integrator 4. In the latter, the signal, proportional to the instantaneous power of the spark, is integrated over the duration of the spark. Simultaneously with the RS flip-flop 9, the one-shot 8 starts up on the front of the first square-wave pulse from the output of the comparator 7 and generates

I at its output is a logical O signal (Fig. 2e). The single-oscillator 8 is restarted along the front of each pulse at the output of the comparator 7, therefore, to ensure continuity of the signal at the output of the single-vibrator 8, the time / specified by its master circuits must be greater than the period of oscillation of the discharge current. At the end of the pulse of the one-shot 8, the pulse shaper 10 outputs a signal to trigger the A / D converter 5 (Fig. 2e), the A / D converter starts and measures the signal at the integrator output.

At the end of the measurement, A1SCh5 generates a signal. The end of measurement, which is fed to the reset input of RS-flip-flop 9 and sets at its output a logic O signal. The logic 0y signal on the RS-flip-flop 9 output closes analog switch 11, the integrator 4. Measurement time A1Sh 5 (for example, for ADC

K572PV1, the measurement time is 110 x), is significantly less than the period of the discharge pulses. The information at the output of the A / D converter 5 after measurement is saved until the arrival of the next bit pulse and in the digital code enters indicator 6, where it is converted into a code of digital indicators. At this point, the measurement of the energy of the spark discharge ends, and the meter is ready to receive information about the energy of the next discharge pulse. The cycle for measuring the energy of a spark discharge is repeated.

Thus, in comparison with the known invention, it is possible to increase the accuracy of measuring the energy released in the spark gap by eliminating from the main measuring circuit of one analog key a sampling-storage device and introducing a corresponding pulse driver and RS-trigger connection, allowing synchronize the switching on times of the integrator and the ADC with the frequency of the measured discharge pulses and their duration, as well as the synchronization of the reset of the integrator with the end of the measurement no ADC. In addition, the information at the output of A1SC remains unchanged until the arrival of the next measurable bit of the current pulse and does not depend on its frequency. The function of the first analog key in the proposed device is performed by the second analog key, since its opening occurs at the moment of the start of the spark discharge (in a semiconductor spark plug at the moment of

ten

15

20

Claims (1)

- 25 transition preparatory stage of the discharge in the spark). Therefore, the integrator integrates the signal only during the spark stage of discharge. Invention Formula A spark energy meter containing voltage and current transducers, a signal multiplier, an integrator, an analog-to-digital converter, an indicator, a comparator, a one-shot and an analog switch, the outputs of the voltage and current measuring transducers being connected to the signal-to-analogue digital output. connected to the indicator input, the comparator input is connected to the output of the current measuring transducer, and the comparator output is connected to the one-vibrator input, the analog switch is on integrator reset circuit, characterized in that, in order to improve measurement accuracy, an RS trigger and pulse shaper are additionally introduced, the output of the signal multiplier is connected to the integrator input, the output of which is connected to the analog-digital converter input, the comparator output is connected to the RS installation input - a trigger, the one-shot output is connected to the input of the pulse former, the output of which is connected to the trigger input of the analog-digital converter, the output. The end of measurement of which is connected to the reset input R S-flip-flop, the output of the latter is connected to the control input of the analog switch. thirty 40 t, J t, e t. FIG. Z Comparator Reference Voltage t Lj L