SU1746519A1 - Pulse shaper - Google Patents

Abstract

The invention relates to a pulse technique and can be used in the construction of measuring devices. The aim of the invention is to obtain from a sinusoidal voltage output pulses with a stable duty cycle of two. The pulse shaper contains resistors 1, 2,11,12,17,18,19 and 22, transistors 4, 5, 6, 14, 15, 20, 21, diodes 8 and 9, input buses 25-1 and 25-2, source power supply with pole 26-1 and common bus 26-2 and output tires 27-1 and 27-2. New is the introduction of transistor 3. capacitor 7, resistors 10, 13, 16 and 23, trigger 24. Thus, when the amplitude or frequency of the alternating voltage changes on the buses 25-1 and 25-2, the current flow through the capacitor 7 in one and in the other direction it is aligned, the duty cycle of the input pulses is maintained at 2. 1 sludge. gn o Ittk o27-f-o / 7-g 2 O SP y

Description

The invention relates to a pulse technique and can be used to generate clock pulses from alternating sinusoidal voltage in measuring devices, in particular in analog-to-digital converters of an integrating type, which have high demands on the stability of the clock pulse duty cycle.

The purpose of the invention is to obtain from the sinusoidal voltage output pulses with a stable duty cycle equal to two, independent of the variation of the nominal values and characteristics of the circuit elements.

The drawing shows the scheme of the proposed pulse shaper.

The pulse shaper contains the first resistor 1, the second resistor 2, the eighth transistor 3, the third transistor 4, the first. transistor 5, the base of which is connected to the second output of resistor t and the emitter of transistor 3, the second transistor b, the base of which is connected to the second output of resistor 2 and to the emitter of transistor 4, capacitor 7, the first plate of which is connected to the base of transistor 3 and emitter transistor 5, the first diode 8, whose cathode is connected to the collector of transistor 6. whose emitter is connected to the second plate, capacitor 7 and to the base of transistor 4, the ninth resistor 10, the first output of which is connected to the anode of diode 8, the third resistor 11, first in the water of which is connected to the anode of the diode 9, the fourth resistor 12, the tenth resistor 13, the fourth transistor 14, the base of which is connected to the second output of resistor 10 and the second output of resistor 12, the fifth transistor 15, the base of which is connected to the second output of resistor 11 and to the first output of the resistor 13, the eleventh resistor 16, the first output of which is connected to the collector of transistor 14, the fifth resistor 17, the sixth resistor 18, the seventh resistor 19, the second output of which is connected to the collector of transistor 15, the sixth transistor 20, the base of which is connected to the second output of resistor 16 and the first output of resistor 17, the seventh transistor 21, whose base is connected to the second output of resistor 18 and to the first output of resistor 19, the eighth resistor 22, the twelfth resistor 23, trigger 24, the first input of which is connected to the second output of resistor 22 and with the collector of the transistor 20, the first 25-1 and the second 25-2 input busbars, which are connected respectively to the first terminal of resistor 1 and to the first terminal of resistor 2, plus a power source 26-1, which is connected to the first terminals of resistors 12 and 22, with

emitters of transistors 14 and 15, if the second output of resistor 13 and the second output of resistor 23, the first output of which is connected to the collector of transistor 21 and to the second input of trigger 24, common power supply bus 26-2, which is connected to the emitters of transistors 20 and 21, with collectors of transistors 3 and 4, with the first output of resistor 18 and with the second output

0 of resistor 17, output lines 27-1 and 27-2, to which the direct and inverse, respectively, outputs of trigger 24 are connected,

A variable sinusoidal voltage is applied to the tires 25-1 and 25-2. Magnitude

5, the voltage of the power supply with a pole 26-1 and a common bus 26-2 is selected based on the elemental base of the device, in which the proposed pulse shaper is used. The capacitance value of the capacitor 7 is chosen such that over half the voltage period on the tires 25-1 and 25-2 the capacitor 7 is charged to a voltage equal to 10-20% of the voltage of the power supply with a pole 26-1 and the total

5 bus 26-2.

The pulse shaper operates as follows.

The operation of the pulse former will be considered from the moment the alternating voltage is applied to the buses 25-1 and 25-2 with the power on, while the capacitor 7 is completely discharged. Assume that at the time the alternating voltage is applied to the bus 25-1 a positive floor 5 is applied. If the bus 25-1 has a voltage greater than the opening threshold for Osc transistor 5, then a current begins to flow along the bus 25-1 circuit - resistor 1 - base-emitter junction of transistor 5 - capacitor 7 0 base-emitter junction of transistor 4 - resistor 2 - bus 25-2. If the voltage on the bus 25-1 with respect to the bus 25-2 is less than Uni, then when the voltage on the bus 25-1 reaches the value}, a current begins to flow along the specified circuit. Transistors 5 and 4 open and current begins to flow through the circuit: plus 26-1 - parallel to the parallel wiring 12 and the emitter-base junction of transistor 14 - resistor 10 - diode 8 - junction collector-emitter of transistor 5 - capacitor 7 - base-emitter junction transistor 4 - common bus 26-2; transistor 14 opens and current begins to flow along the circuit: plus 26-1 - emitter-collector junction of transistor 14 - resistor 16 - parallel connected resistor 17 and base-emitter junction of transistor 20 - common bus 26- 2 Transistor 20 opens, and a voltage appears across its collector that is close to

five

0

five

zero, and the trigger 24 is set to a single position. A single signal appears on bus 27-1, and a zero signal appears on bus 27-2. In this case, since transistors 6 and 3 are closed, both transistors 15 and 21 are closed and the collector of transistor 21 is positive, with a level within the range of a single signal voltage.

During the positive field of the wave on bus 25-1, the capacitor 7 is charged along the circuits from bus 25-1 to bus 25-2 and from the current source from pole 26-1 and common bus 26-2 in such a way that positive the potential will be on the plate connected to the emitter of the transistor 5. When the positive half-wave collapses on the bus 25-1, the transistor 5 closes (and at a voltage equal to Un + U where U is the voltage on the capacitor 7} and, accordingly, transistors 14 and 20 and a single signal is set at the collector of transistor 20. Next, on bus 25-2, it starts positive (with respect to the bus 25-1) half-wave of alternating voltage. At a voltage equal to the opening threshold of the transistor 6 Una (taking into account the charge of the capacitor 7) at the base-emitter junction of the transistor 6, a current flows through the circuit: bus 25-2 - resistor 2 - base-emitter junction of transistor 6 - capacitor 7 - base-emitter junction of transistor 3 - transistor 1-bus 25-1. Transistors b and 3 open and current begins to flow along the circuit: plus 26-1 - in parallel connected resistor 13 and the transition emitter-base transistor 15 - resistor 11 - diode 9 - transition ollektor-emitter transistor 6 - capacitor 7 - base-collector junction of transistor 3 - total bus 26-2. The transistor 15 opens and current begins to flow along the circuit: plus 26-1 - emitter-collector junction of transistor 15 - resistor 19 - parallel-connected resistor 18 transistor base-emitter of transistor 21 - bus 26-2.

Transistor 21 opens and a voltage close to zero appears on its collector, and trigger 24 is set to zero. A zero signal appears on bus 27-1, and a single signal appears on bus 27-2. Thus, a single impulse is formed on bus 27-1, and a zero impulse is formed on bus 27-2. Since during the action of the positive half-wave of the alternating voltage on the bus 25-2 a current flowed through the capacitor 7, the direction of which is opposite to the direction of the current flowing under the action of the positive half-wave on the bus 25-1, the capacitor 7 is recharged, Depending on the current flow times under the action of the positive half-wave on the bus 25-1 and under the action of the positive half-wave on the bus 25-2 on the capacitor 7, the alternating voltage can be charged, the positive pole of which can be on any of capacitor capacitor 7. The presence of a positive charge pole on the plate connected to the emitter of transistor 5 leads to the fact that the opening of transistor 5 will occur when the voltage on the bus 25-1. more uni. and thereby reduces the time of current flow through the capacitor 7, the presence of a negative charge pole on the same plate of the capacitor 7 leads to the fact that the opening of transistor 5 will occur when the voltage on the bus 25-1 is less than Uni, and thereby increases the time of current flow through the capacitor 7. Similarly, the time of current flowing through the capacitor 7 decreases or increases, depending on the magnitude and polarity of the charge, with a positive half-wave on the bus 25-2. After the alternating voltage is applied to the buses 25-1 and 25-2 after 20-30 periods (obtained experimentally), the recharge process is stabilized, the current flow times through the capacitor 7 under the action of the positive half-wave on the bus 25-1 and under its action on the bus 25-2 becomes strictly equal and the pulse duty ratio on the output tires 27-1 and 27-2 will be equal to 2,

When the amplitude or frequency of the alternating voltage on tires 25-1 and 25-2 varies, the flow times through the capacitor 7 in one direction and in the other direction are equalized and the duty cycle of the output pulses remains equal to 2.

Experimental studies of the layout of the proposed pulse driver showed that the device is not critical to the accuracy of manufacture and variation of the parameters of the constituent elements (resistors, capacitor, diodes, and transistors) and with fluctuations in the amplitude and frequency of the alternating sinusoidal voltage, maintains the duty cycle of the output pulses of 2.

Claims (1)

Invention Formula The pulse shaper containing the first and second input bus, the first resistor, the first transistor, the base of which is connected to the second output of the first resistor, the second resistor, the second a transistor, the base of which is connected to the second-first capacitor plate and to the emitter of the second resistor, the first and first transistors, whose collector is the second diode, the third and fourth transistor is connected to the cathode of the first diode, the anode stor, the base of which is connected to the second through the ninth resistor to the fourth resistor's connection, the fifth is transfered to the base of the fourth transistor, the collector, the base of which is connected to the second torus of which through the eleventh resistor to the output of the third resistor, p and the neck The sixth transistor, the resistors of the seventh resistor, the first emitter of which is connected to the second output of which is connected to the second output of the water of the fifth resistor, the first output of the sixth resistor, the eighth resistor, the neck resistor, the collector of the eighth transistor, base the transistor and the third-collector are connected to the first terminal of the fifth resistor, a seventh-sistor, the base of which is connected to the second my transistor, the power supply pole, a capacitor plate and an emitter that is connected to the first transistor One of the four transistor, the collector of which is a turned resistor and the first terminal with an eighteen key to the cathode of the second diode, an anode resistor, the second terminal of which is connected to the first terminal, the third one is connected to the collector of the sixth transistor-resistor, the second output of which power source, which keys to the first terminal of the tenth one is connected to the emitter of the seventh transistor resistor, the second terminal of which is connected to the second terminal of the fifth resistor, output pole to the power source In this case, a fifth transistor and a second output two to obtain from a sinusoidal resistor, the first output of which the output pulses from the stable one are connected to the second trigger input and a duty cycle equal to two , the collector of the seventh transistor, the base is co-entered with the ninth, tenth, eleventh and 25th of which is connected to the first output of the seventh to twentieth resistors, the eighth transient resistor, the second output of which is a stopper, a capacitor and a trigger, whose outputs are connected to sewer collector the first is connected to the output buses, the second input bus is connected to the first input bus connected to the first terminal of the second resistor, the second terminal of the first resistor, the second terminal 30 of which is connected to the third emitter its transistor, the first input of the trigger of the connecting transistor, the base of which is connected to the collector of the sixth transistor.