SU1647874A1 - Device for voltage comparison - Google Patents

Abstract

The invention relates to a pulse technique and is intended to build comparison devices for the level of two voltages. The purpose of the invention is the extension of the field of application due to the possibility of comparing the input signal with the reference modulo device - achieved by the introduction of resistors 15, 16, an additional resistor 17 and an additional transistor 8 with a conductivity opposite to the main transistor 7. The device also contains a bus t reference voltage source, input signal bus 2, comparator 3, resistors 4,5,10, 11 common bus 6, main transistor 7, output bus 9, power source bus 12 and diodes 13, 14. 1 Il.

Description

The invention relates to a pulse technique and is intended to build a comparison device at the level of two voltage. genius.

The aim of the invention is to expand the scope by providing the ability to compare the input signal with the reference modulo.

The drawing shows a schematic diagram of a device for comparing stresses.

The device contains a bus 1 of the reference voltage source, an input signal bus 2, a comparator 3, the first 4 and second 5 resistors, a common bus 6, a main transistor 7, an additional transistor 8, an output bus 9, a third resistor 10, a fourth resistor 11, a source bus 12 power supply, first 13 and second 14 diodes, fifth resistor 15, sixth resistor 16 and additional resistor 17, the non-inverting input of the comparator 3 is connected to the input bus 2, the inverting input is connected to the bus 1 of the reference voltage source and the common bus 6 through the first 4 and second 5 resistor - 25 ry, and output through the third resistor 10 is to the base of the main transistor 7. The emitter of the additional transistor 8 is connected to the common bus 6, the collector to the output bus 9 and through the fourth resistor 11 to the power supply bus 12, and the base is connected through the fifth resistor 15 to the collector of the main transistor 7. the base of which is connected through the sixth resistor 1.6 to the bus 1 of the reference voltage source and to the second terminal of the first diode 13, the first terminal of the main transistor 7 connected to the emitter. The second terminal of the second diode 14 is connected to the output of the comparator 3.

The device operates as follows.

The voltage on the bus 1 of the reference voltage source is equal to the saturation voltage of the comparator 3. Resistors 4 and 5 form a resistive divider with a division ratio K of the value of the reference voltage Uo on the bus 1 of the reference voltage source. The comparator 3 generates a voltage and _{outputs of} positive polarity on the output bus 9 only at those times when the reference Uo and the input voltage Ubx on the buses 1 and 2 are of the same sign and the input voltage U _{BX is} greater than the value Uo K.

For example, with voltages Uo and U _B x of positive polarity, a positive polarity voltage occurs at the output of the comparator 3 at the indicated ratio, therefore, transistors 8 and 7 are closed and a high positive voltage takes place on the output bus 9.

With Up and Ubx of negative polarity, a negative polarity voltage occurs at the output of the comparator 3, therefore, transistors 7 and 8 are also locked and a positive polarity voltage is generated at the output.

In that case, if the voltages on buses 1 and 2 of different polarity with amplitudes are approximately equal, then the voltage q of the output of comparator 3 has the opposite polarity with respect to the voltage on bus 1. Moreover, transistors 7 and 8. are saturated and U _Bb ix is zero ..

If voltages of the same polarity are observed on buses 1 and 2, but the voltage Ubx is less than the voltage U _o * K, then the output of the comparator 3 has a voltage of opposite polarity, with respect to the voltage polarity on bus 1 and transistors 7 and 8 are saturated. There is no output voltage on bus 9.

Thus, the comparator 3 generates a voltage at its output only when Uo and Ubx are of the same sign and the amplitude υ _β χ is greater than Uo.

In those cases where buses 2 and 1 are not connected anywhere, due to the fact that a positive voltage is supplied to the bus 2 from the bus through the resistor 17, a voltage of positive polarity takes place at the output of the comparator 3. Transistors 7 and 8 are saturated and the output voltage is equal to the log. 0. The resistance value of the resistor is chosen much more than the output resistance of the source Ubx. connected to bus 2, so it does not affect the readings of the comparator.

Claims (1)

Claim A device for comparing voltages, containing a comparator whose non-inverting input is connected to the input i bus, the inverting input to the bus of the reference voltage source and the common bus, respectively, through the first and second resistors, and the output through the third resistor to the base of the main transistor, two diodes, coI united by the first conclusions. the fourth resistor, the output bus, characterized in that, in order to expand the scope by providing the possibility of comparing ”the input signal with the reference modulo, the fifth and sixth resistors, an additional transistor with a conductivity opposite to the main transistor, are introduced, while the emitter is additional the transistor is connected to a common bus, the collector is connected to the output bus and through the fourth resistor to the power supply bus, and the base is connected through the fifth resistor to the collector of the main transistor, the base of which connected through the sixth resistor to the bus of the reference voltage source and the second terminal of the first diode, the first terminal connected to the emitter of the main transistor, and the second terminal of the second diode 5 is connected to the output of the comparator.