CS235239B1 - Linearized optoelectronic converter with zero indicator - Google Patents

Abstract

The purpose of the invention is to linearize the transmission characteristic of an insulating member with two optocouplers of different properties and also to sensitively indicate the zero value of the input signal. This is achieved by connecting two non-matching terminals of the receivers of both optocouplers (6, 7) to the input of the current amplifier (12), while the driver of the input optocoupler (6) is connected to the one-way side of the diode bridge (5), whose alternating side is connected between the output and the feedback input of the voltage-current converter (3), to which the input signal is supplied, while the driver of the output optocoupler (6) is connected between the output of the current amplifier (12) and the input of the linearizing current-voltage converter (13) with linearizing potentiometers (14). The output of this converter (13) is connected to the input of the polarity switch (15), from which an analog output is derived and which has a switching input connected to the output of one of the two comparators (23, 24) connected to the output of the signed optocoupler (20). The driver of this signed optocoupler (20) is connected between the output of the voltage-current converter (3) and the bias voltage source (21). Comparators (23, 24) have two logic outputs (25, 26) for indicating the polarity and zero value of the input signal.

Description

235239 4

The invention solves the linearization of the conversion characteristics of the insulating member with the pair of unpaired optocouplers and the sensitive indication of the zero value of the input signal.

Up to now, known optoelectronic transducers are linearized by paired opto-couplers in wiring to compensate for the same two non-linearities. The transmission of the signals of the two polarities is resolved by setting a suitable working point in the area of the least nonlinearities of the two optrons used. Typically, these optoelectronic transducers do not have an indication of the zero value of the input signal, or rather, then its sensitivity is relatively small.

The aforementioned drawbacks are eliminated by the zero linearized optoelectronic transducer according to the invention, in which the pair of unpaired optocouplers has two mutually discordant receiver terminals coupled to the unipolar current amplifier input, the output optocoupler terminals being connected to a single direction the side of the diode bridge that the alternating side is connected to the output of the on-the-current converter, to which the sensing side is connected. The outputs of the driver of the second, output optocoupler are connected between the output of the unipolar current amplifier and the input of the unipolar linearization current voltage converter which has the linearization potentiometer of which the output is connected to the polarity switch from which the linearization output is output an optoelectronic transducer and having a switching input connected n, and one of the two logical outputs of a pair of comparators. The comparators are inversely connected to each other and their inputs are connected to the output from the receiver of the next sign optic. The sign optic output is simultaneously connected to the balancing potentiometer, and the driver of this optocoupler in series with the limiting resistor is connected between the output of the voltage-current transducer and one pole of the bias source. The second pole of the bias source, together with one of the pair of steam-current transducer inputs and one field of the sensing shunt, is coupled to the insulated ground, while the other portion schematically represents a common outlet formed as a separate ground. Connecting the optocouplers to the unipolar current amplifier and the input opto-exciter output to the output of the diode bridge or output opto-exciter, the unipolar current amplifier output and the unipolar linearization current-to-voltage converter input, is connected to the opto-coupler in which identical components of optron nonlinearities are compensated for and differences in nonlinearities are compensated for in a uni-polar linearization current-to-voltage converter. The advantage of the unipolarity of signal processing, i.e. the processing of only one signal polarity, is that by linearizing one branch of the transmission characteristic, it simultaneously obtains linearity for both polarity signals. It is not necessary to set the workstation points for which thermally stable and time-stable sources are required. A new effect is also achieved by virtue of the fact that virtually any pair of optrons of considerable different properties can be used. By connecting the sign to the output of the voltage-current transducer, where an alternating side-link bridge is connected, it is possible to indicate both the polarity of the input signal and a very sensitive indication of the zero value of the input signal. In doing so, by connecting one of the logic outputs to the switching input of the pre-polarity switch, both of the transmission characteristics of the optoelectronic transducer are unipolarized by connecting the diode bridge to the output of the on-current converter.

In the accompanying drawing, there is shown a circuit diagram of a particular embodiment of a linearization-to-electronic converter with a zero indicator.

In the figure, one pickup terminal 1 is connected via an input resistor 2 with an inverting input of an operational amplifier, ie a voltage-current transducer 3, whose non-inverting input is coupled to an insulated ground 4 with a second terminal of the sensing shunt. The transducer 3 and its inverting input are connected to the alternating side of the diode bridge 5. On the one-way side of the diode bridge 5 is connected an input optic S whose receiver collector outlet is connected to the first terminal 19 of the first source 8 with a second semi-ground. The emitter terminal of the receiver and input opto-coupler 6 is coupled to the collector terminal of the output opto-coupler 7 and is also coupled to the inverting input of the additional operating amplifier, i.e., a uni-polar current amplifier 12 with a non-inverted grounded input. The emitter terminal of the output optocoupler 7 is connected to the terminal 11 of the second source 9 with a second grounded field. The cathode is connected to the output of the polarity current amplifier 12 and the output optor 7 anode is connected to the input of the unipolar polarization current-voltage converter 13. The linearization potentiometers 14 are the components of the unipolar linearization current-voltage converter 13, the number of which is The output on the output, which is signifi- cantly aligned with the output at the input of the unipolar linearization current-voltage converter 13, is connected to the switched input 16 of the switch polarity 13, with a further pair of sign-like input and output terminals of the converter 13. is grounded. The switched input 235239 5 16 of the polarity switch 15 is connected via the resistor 151 to an inverting input, and via a pair of resistors 152 and 154 in series coupled to a non-vertically input of the operational amplifier 155, a reverse signal 153 is connected to the node. the emitter of the grounded collector-base transistor 157 through the resistor 156 connected to the switch input 17 of the switch polarity switch 15. The switching input 17 is connected by a first logic output 25 of the inverting comparator 23, which includes an operational amplifier 233 with an output connected via a zener 234 to the Zener cathode the ground anode diode 235 and the first logic output25, wherein the non-inverting input of the operational amplifier 233 is via a resistor 232 grounded and resistor 213 connected to the second terminal 11, while its inverting input is via a resistor 231 connected to the emitter emitter node of the opto-coupler receiver 29 with a collector connected to the first light and a non-inverting comparator 24 connected to the described node via a resistor 242 connected to the inverting input of the operational amplifier 243, which inverted the input is earthed through resistor 241 and coupled to resistor 246 via resistor 246, and the output is via a resistor 244 connected to the cathode of the Zener diode 245s by a grounded anode and also to a second logical output 26. connected to the output of the voltage-current transducer 3 and the exciter cathode is connected to one outlet of the bias source 21 with a second terminal connected to the insulated ground 4.

The voltage signal of the given polarity from the sensor shunt 1 is converted into a proportional current signal corresponding to the direction in the voltage-current transducer 3, however, the light-emitting diode, thus the driver of the input optocoupler 5, flows only one direction after rectifying the diode bridge 5. stripping the input signal using an optical transmission channel. According to this optocoupler 6, the emitter of its phototransistor always supplies a positive current of the respective value to the inverting input of the unipolar current amplifier 12. This high current current amplification and the output of the luminous diode, ie the output opto-exciter 7 which is connected in the negative wiring of the unipolar current amplifier 12. The current of the photo-transistor collector, ie the receiver of the output optic 7, which is always negative from the node in question, is compensated for by the high current amplification the unipolar current amplifier 12, the current of its inverting input almost to zero. If the current transmission characteristics of the opto-couplers 6 and 7 were complete, then the current of the output optocoupler exciter 6 would have to be the same as the current of the input opto-coupler 6. No further linearization would be required. The deviations of the characteristics of the two optocouplers 6 and 7, respectively, are compensated by the linearization potentiometers 14 of the unipolar linearization current-to-voltage converter 13 through which the output current of the output optocoupler 7 flows. one wind characteristic of an optoelectronic transducer, corresponding to the positive or negative polarity of its input signal, exactly coincides with the theoretical linear characteristic. Both polarities of the optoelectronic transducer output voltage 18 are obtained by a polarity switch 15, in which, based on the signal at the switching input 17, the output voltage from the unipolar linearization current-voltage transducer 13 is fed only to the inverting input of the operational amplifier 155 when the jet transistor 157 saturated, the second time again the inputs with blocked transistor137. In the first case, the voltage polarity switch is 11, in the second case it is a voltage transmitter +1. The transistor 157 is also triggered by the H-level signal at the first logic output 25 that occurs when the input of the linearized optoelectronic transducer is positive voltage. At that time, it is also necessary to apply a voltage from the unipolar output of the current-voltage or voltage converter 13, which is always negative, to invert so that a positive voltage is applied to the output 18.

Two logical signals, at the first logical output 25 and the second logical output 26, for separate indication of the input-signal polarity by the H-level and its zero-value by the L-level at both outputs simultaneously, are obtained by means of the optocoupler 29, the inverting comparator 23 and the non-inverting comparator. 24. The logic levels at the outputs of the two comparators 23, 24 are adjusted by the help of the Zener diodes 235 and 245, respectively. The highly sensitive indication of the input signal's zero value is that the current flowing from the voltage-to-current converter 3 of the diode bridge 5 flows always through a triple diode in series. The voltage signal at this triple diode is a logarithmic downstream function. Even with very low current values, the voltage drop is given by the sum of the diode threshold voltages and is now large. In order to transmit the zero-value signal to information about the signal of the linearized-to-electronic converter input signal, the three-valued logic opto-coupler 20 operates. With a positive input voltage that inverts to the negative current transducer 3, the sign optic 20 is closed,

Claims (1)

235239 7 because on the cathode of its driver there is a negative voltage from the bias source 21, which is more costly than the voltage at the anode. At a negative input voltage, the voltage-to-laundry converter 3 at the anode of the exciter opener 20 has a positive voltage and hence its maximum current. The zero input voltage corresponds to the approximate half value of the garment of the sign optic 20. At this value, the approximate voltage at the inputs of the two comparators 23, 24 is set by the balancing potentiometer 22. Suitable polarities and sizes of the reference voltages supplying the non-inverting input of the opener 233 via the resistor 235, respectively the 24S to the inverting input of the op-amp 243, to ensure that at the approximate voltage at the inputs of both comparators 23 and 24 respectively, they will be on the first and second outputs, respectively, a second-logic output 28, at the same time an L-level indicating a zero value of the zero signal input signalulearised optoelectronic transducer. OBJECT Linearized, zero-indicator optoelectronic transducer incorporating optocouplers, voltage-to-current transducer, diode bridge, unipolar current amplifier, unipolar linearizing laundry-to-to-wire converter, semiconductor switch polarity, two amplitude atrial comparators of unidirectional source, indicated by the female dipole input of the voltage-laundry transducer (3) is connected to the sensing side (1), connected at one end to the insulated earth (4), the AC input of the diode bridge (5) is connected between the output of the voltage-current converter (3) and the optocoupler driver (6) is connected in one direction, the receiver of which is one outlet connected to the first terminal (10) of the first source (8) with the second grounded field and the second terminal being together with the mismatched output of the output opto receiver (7) associated with one unipolar input field a second amplifier (12) with a second ground grounded, wherein the remaining output of the output optic receiver (7) is connected to a second terminal (11) of the second source (9) with a second grounded field and an output optocoupler (7) the intermediate unipolar laundry amplifier (12) and the unipolar linearization-voltage converter (13) input are connected to the non-polarizing potentiometers (14) with the grounded second pole, while the unipolar linearization laundry / voltage converter output (13) a switched input (16) of the polarity switch (15) is connected to the output (18) and the switching input (17) connected to the first logical output (25) of the inverting comparator (23), or to the second non-inverting logic output (26) the comparator (24), the ungrounded inputs of both comparators (23 and 24) being connected to the output of the opto-coupler (20), whose exciter is connected via a resistor (19) m the output of the in-line current transducer (3) and the outlet of the inlet source (21) with the second output connected to the insulated earth (4). 1 sheet of drawings