SU1495984A1 - Pulse shaper - Google Patents

Abstract

The invention relates to a measurement technique and can be used in thermistor microwave power measurements. The purpose of the invention is to increase the reliability of the pulse driver by eliminating the through currents, which allows to reproduce arbitrary waveforms with high accuracy. It is achieved by the fact that the power source 2 is made on the source voltage 9 and the inverting voltage follower 10, the summation unit 3 is made on the operational amplifier 11 and (2n + 1) resistors 12-20. The pulse shaper also contains a control unit 1, p-keys 4-7. 1 il.

Description

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The invention relates to a measurement technique and can be used in thermistor meters of SEC,

The purpose of the invention is to improve the accuracy of pulse formation.

The drawing shows an electrical block diagram of a driver of four ipex keys.

The pulse shaper contains a control unit 1, a power supply source 2, a sug-shaking unit 3, the first 4, a third 5, a third 6, and the fourth 7 keys, the control inputs of which are connected to the corresponding inputs of the control unit 11 , the output of the summation unit 3 is connected to the output bus 8, the power supply 2 is made on the reference voltage source 9 and the inverting voltage follower 10, and the summation unit 3 is made on the operational amplifier 11 and nine resis- JTOpax 12 - 20, with the first conclusions of the first 12, second 13, third 14, fourth 15 and p In addition, 16 resistors are interconnected and IK connected to the input of operational amplifier 11, the output of which is the output of blog 3 of summation, the second terminals of the first, second, third and fourth resistors are connected to the inputs of the corresponding switch 4-7 and the first terminals respectively sixth 17, {seventh 18, eighth 19 and nine: 20 resistors, the second conclusions of the sixth 17 and eighth 19 resistors are interconnected and connected to the output of the inverting repeater 10, the input of which is connected to the output of the source 9 of the reference voltage and ormi the Output; MI of claim 16, 18 seventh and ninth resistor 20, the outputs of the first 4, second 5, third 6 and fourth 7 Clue

11, a predetermined voltage and voltages of the power source 2 are formed. With the help of resistor 16, a constant signal output component can be entered, using keys 4-7 and resistors 12-20, a complex output signal can be obtained up to a stepwise approximation of the arbitrary signal. for1-1Ы. Pulses can be obtained in a more complex form than a meander (for example, such as a mausoleum, etc.). The operational amplifier 11 amplifies the output voltage of the source 9 of the reference voltage or of the inverting repeater 10.

During the absence of control pulses, the electronic switches are open, the corresponding inputs of the operational amplifier 11 are connected to the common bus of the device and only a constant component is present at its output. Through-circuit short-circuit currents do not occur, since the currents are limited to the first resistors 17-20.

Despite the fact that electronic switches 4-7 are not covered by feedback as in the known driver, and their residual voltage is fully included in the error in the formation of the amplitude of the pulses, its magnitude is sufficiently small. For example, when using an inversely connected transistor or a compensated key of type 101 KT as a key, the residual voltage will not exceed 1 mV, which, when the voltage of the power supply 2 is equal to 10 V, will be 0.01%. The error of setting the | amplitude of the output signal due to the difference between the positive and negative amplitudes does not exceed one thousandth of a percent.

Building an inverting repeater 10 on a 140UD17 chip allows

whose connected to the common bus source is 45 get the difference between the output

ka 9 reference voltage.

The shaper works as follows.

From the input device

the voltage source 9 of the reference voltage and the inverting follower 10 voltage is not more than 0.1 mV and the magnitude of the relative error at

pulses in the control unit 1 form the voltage of 10 V not more

There is a definite sequence, for example, four sequences of pulses of the required duration, determined by the pattern, 001%.

Thus, the amplitudes of positive and negative pulses are equal to each other. The absolute magnitude on the time axis (on the basis of the amplitude can be changed

bypassed output waveform). During the operation of these pulses, the corresponding switches 4-7 are closed and at the output of the operational amplifier

only the magnitude of the feedback resistances in the opamp circuit 11, i.e. use of the device provides increased reliability

the voltage of the source 9 of the reference voltage and the inverting follower 10 of the voltage is not more than 0.1 mV and the value of the relative error at

0.001%.

Thus, the amplitudes of positive and negative pulses are equal to each other. The absolute magnitude of the amplitude can be changed by changing

only the magnitude of the feedback resistances in the opamp circuit 11, i.e. use of the device provides increased reliability

operation by eliminating through currents, and allows for highly accurate iproduction of arbitrary waveforms.

Claims (1)

The invention includes a pulse driver comprising a control unit, a power source, a summation unit and n keys, the control inputs of which are connected to the corresponding outputs of the control unit, the output of the summation unit, in order to improve accuracy. pulse generation, the power source is made on the source of the reference voltage and the inverting voltage follower, and the summation unit is made on the oner-amplifier and 2n + 1 resistors, the first conclusions of the first, second When, ..., (2n-f1) -ro resistors are interconnected and connected to the input of the operational amplifier, the output of which is the output of the summation unit, the second terminals of the first, second, .., nth (2n + 1) -th resistors are connected to the inputs of the corresponding switches and the first terminals respectively (nil) -ro, (n + 2) -th (n + +3) -th, ..., 2n-th resistors, the second terminals (n + 1 ) th, (n + 3) -th resistors are interconnected and connected to the output of an inverting repeater, the input of which is connected to the output of the reference voltage source and the second terminals of the (n + 2) -th, ..., 2nth l and (2p + 1) resistors, the outputs of the n keys are connected to the common bus of the voltage source.