SU1661970A1 - Pulse generator - Google Patents

Abstract

The invention relates to a pulse technique and can be used in automation devices as a stable generator of short pulses. The aim of the invention is to increase the stability of the frequency of the output pulses with a change in the supply voltage and temperature. The goal is achieved by compensating the destabilizing factors with the help of the N 1 -N-type integrating transistor, the first 7, second 8 and third 9 diodes, the fourth 13, fifth 15, sixth 4 and seventh 14 resistors. In this case, the first output of the first resistor 12 is connected via the second resistor 11 to the power supply bus 17, through the diode 8 to the output bus 18 and through the collector-emitter junction of the transistor 6 with the power bus 17 and through the third resistor 16 to the common bus 19, and through the diode 7 with the base of the transistor 5, which through the fourth resistor 13 is connected to the emitter of the transistor 5 and through the seventh resistor 14 to the collector of the integrating transistor 1. The collector of the integrating transistor 1 through the timing of the driving capacitor 2 is connected to its base, which Belt resistor 3 is connected to a power bus 17, through the collector-emitter junction of transistor 10 - the common bus 19. The base of transistor 10 via a fifth resistor 15 is connected to the output bus. In this case, the collector of the transistor 5 is connected to the base of the transistor 6, and the third diode 9 is connected by a cathode to a common bus, and the anode to the second output of the first resistor 12. 2 Il.

Description

common bus 19. The base of the transistor 10 through resistor 12. 2 Il.

The invention relates to a pulse technique, a class of relaxation generators, and can be used in various automation devices as a stable generator of short rectangular pulses.

The aim of the invention is to increase the stability of the frequency of the output pulses when the supply voltage and temperature change by compensating destabilizing factors.

FIG. 1 shows an electrical schematic diagram of a pulse generator; Fig. 2 shows the voltage plots on the first Ucl and second UC2 capacitor plates.

The pulse generator contains an integrating transistor 1, a capacitor 2, a variable 3 and current limiting A resistors, a regenerative switch made on transistors 5 and 6, diodes 7-9, transistor 10, voltage divider on resistors 11 and 12, resistors 13-16, bus 17 power supply, output bus 18 and common bus 19.

The emitters of transistors 1 and 10 are connected to common bus 19, the collector of transistor 10 is connected to the base of transistor 1, the first face of capacitor 2 and the first lead of resistor 4, the second lead of which is connected to power bus 17 via variable resistor 3, the collector of transistor 1 is connected to the second lead the capacitor 2 and through the resistor 14 to the emitter of the transistor 5. The first lead of the resistor 12 is connected through the resistor 11 to the power supply bus 17, the first lead of the resistor 16 is connected to the common bus 19. The collector of the transistor

6 is connected to the output bus 18, with the second output of the resistor 16, with the anode of the diode 8 and through the resistor 15 with the base of the transistor 10. The emitter and the base of the transistor 6 are connected respectively to the power bus 17 and the collector of the transistor 5, the base of which is connected to the cathode of the diode 7 and through resistor 13 with transistor emitter 5. Anode diode

7 is connected to the cathode of the diode 8 and to the first terminal of the resistor 12, the second terminal of which is connected to the anode of the diode 9, the cathode of which is connected to the common bus 19.

The pulse generator works as follows.

When applying the supply voltage

the power supply bus 17 in the circuit: resistor 11, diode 7, base-emitter junction of transistor 5, resistor 14, capacitor 2, base-emitter junction of transistor 1 appears current,

opening transistors 1 and 5. The collector current of transistor 5 opens transistor 6, an avalanche-like switching on of transistors 5 and 6 occurs, and a voltage appears on the output bus 18. The process of forming the output im-. The current flowing through the resistor 15 opens the transistor 10 and connects the first plate of the capacitor 2 and the base of the transistor 1 to the common bus 19,

thus closing the transistor 1. The voltage on the first capacitor plate decreases almost to zero (Fig. 2, section a). On the output bus 18, a steep rising front is formed.

The voltage on the output bus 18 becomes almost equal to the supply voltage of the device. The capacitor is quickly charged through a relatively small resistance of the resistor 14 (Fig. 2, portion b) to a voltage that is lower than the supply voltage by the magnitude of the total voltage drop at the base-emitter junction of the transistor 5, forward-aligned diodes 7 and

5 8 and in the area of the emitter-collector of the saturated transistor 6.

The moment comes when the charge current of the capacitor stops, the transistors 5 and 6 of the regenerative key are avalanche-like

0 closes, the voltage on the output bus 18 quickly drops to zero, the process of forming the output pulse ends. The diode 7 and the resistor 13 improve the closing conditions of the transistor 5.

5 The transistor 10 quickly closes, the voltage across its collector increases abruptly from zero to the opening voltage of the base-emitter junction of transistor 1 (Figure 2. Section c). The voltage jump is transmitted through a capacitor to the emitter of transistor 5 with the same amplitude (Fig. 2, section d).

Transistor 1 from the closed state goes to linear mode. The capacitor begins to discharge through the collector-emitter section of transistor 1, the device's power source, and the total resistance of resistors 3 and 4 (Fig. 2, section d). This ensures a high degree of constancy of the discharge current of the capacitor, which, in turn, ensures the stability of the pause between pulses.

As the capacitor is discharged, the voltage on its second plate decreases. When this voltage becomes less than the voltage set by the voltage divider by the magnitude of the total voltage drop at the base-emitter junction of transistor 5 and at the forward-displaced diode 7, the regenerative switch transistors 10 and the transistor 10 turn on. a capacitor voltage surge occurs (Fig. 2, portions e and g).

The formation of the next output pulse begins.

Further described processes in. the generator is repeated.

The duration of the output pulses is significantly less than the pause between pulses (50–1000 times); therefore, it does not have a significant effect on the pulse duration and can be ignored.

Taking into account the Ube base-emitter junction voltage of the integrating transistor 1, the discharge current of the capacitor is

, E - ibe

1 bit -

R

razr.

where E is the supply voltage;

Rpasp. - The total resistance of the resistors 3 and 4.

The threshold voltage inclusion of the regenerative key (relative to the power bus 17) has the form

Unop (E - Ug)

Rn

Rn + Ri2

(2)

where E is the supply voltage;

Ug is the voltage drop across the on-set diode 9;

 RII -5 ----- division ratio by H .11 + H.12

The terminals on resistors 11 and 12.

In formula (2), the total voltage drop at the base-emitter junction

transistor 5 and the displaced diode 7 is not taken into account, because it in the process of charging-discharging the capacitor shifts the threshold turn-on voltage and the threshold turn-off voltage of the regenerative key by the same amount and, therefore, the effect of the pause between pulses is not renders.

Taking into account (1) and (2), the duration T of the pause between pulses is

t C Unop Rl1pg E - Ug

WT Rn + Ri2 bit E-i6e

where C is the capacitance of the capacitor. Since Kbe Ug

20

 R g T Rn + Ri2Rpa3pC

those. the duration of the pause between pulses is almost constant. The effect on the pulse frequency of such a destabilizing factor as the 11be of the integrating transistor is compensated for by the voltage drop across the direct-current-diode 9.

The effect on the pulse frequency of the voltage jump on the collector of the integrating transistor is compensated by the voltage drop on the diode 8, which is displaced during the charging of the capacitor. Thus, when the supply voltage changes, these

destabilizing factors. Since it is these factors that mainly determine the temperature dependence, the stability of the following frequency is increased.

output pulses with temperature.

The proposed pulse generator can be performed on virtually any silicon transistors and diodes. The integrator should be performed on a transistor with a sufficiently large current gain to ensure that the pulse duty cycle can be varied over a wide range.

The pulse generator is implemented on the K1315G transistors and the KT361G transistor as an output. The pulse generator operates stably in the range of supply voltages of 3-50 V. In this voltage range, the change in the frequency of the output pulses does not exceed 5-6%. In particular, when the voltage of the pulse generator power supply varies from 3 to 9V and from 9 to 50V, the change in the pulse frequency does not exceed 2-4% and 1-2%, respectively, over a wide range of pulse duty ratio (from 50 to 1000).

The proposed generator does not require the use of matched transistors and can be implemented on almost any widely used transistors.

Unlike the prototype, the connection to the output bus of a pulse generator of permissible load does not affect the generation frequency, since it does not shunt the voltage divider entering the generator.

F o rumula and z obrete n and

A pulse generator containing a regenerative key on the first and second transistors of different conductivity types, a third npn-type transistor whose emitter is connected to a common bus, a capacitor, a variable resistor, a voltage divider on the first and second resistors, the first output of the first resistor through the second the resistor is connected to the power bus, the third resistor, the first output of the third resistor is connected to the common bus, and the collector of the first transistor is connected to the output bus, the output bus and the power bus, characterized in that ysheni stability repetition rate of output pulses at izmegЈ

Editor O. Golovach

Compiled by V.Yakimov Tehred M. Morgental

In addition to supply voltage and temperature, an npn-type integrating transistor, the first, second and third diodes, the fourth, fifth, sixth and seventh resistors are additionally introduced, the collector, the emitter and the base of the pnp-type first transistor are connected respectively, with the second output of the third resistor, the power supply bus and the collector of the second p-pn-type transistor, the base of which is connected to the cathode of the first diode and through the fourth resistor connected to the emitter of the second transistor, the anode of the first diode is connected to the first output of the first resis torus and the cathode of the second diode, the anode of which is connected to the collector of the first transistor and through the fifth resistor is connected to the base of the third transistor whose collector is connected to the base of the integrating transistor, the first capacitor plate and the first output of the sixth resistor, the second output of which is connected to the bus through a variable resistor power, the emitter of the integrating transistor is connected to the common bus, the collector of the integrating transistor is connected to the second capacitor plate and through the seventh resistor is connected to the emitter m second transistor, the second terminal of the first resistor connected to the anode of the third diode, the cathode of which is connected to the common bus.

one

Par.2

Proofreader M.Kucher va

Claims (1)

Claim A pulse generator containing a regenerative switch on the first and second transistors of different types of conductivity, a third pnp type transistor, the emitter of which is connected to a common bus, a capacitor is 20 torr, a variable resistor, a voltage divider on the first and second resistors, the first the output of the first resistor through the second resistor is connected to the power bus, the third resistor, the first output of the third resistor is connected to the common bus, and the collector of the first transistor is connected to the output bus, the output bus and the power bus, characterized in that, for the purpose of to increase the stability of the output pulse repetition rate 30 when the supply voltage and temperature change, an npn-type integrating transistor, first, second and third diodes, fourth, fifth, sixth and seventh resistors are additionally introduced into it, with the collector, emitter and base of the first transistor p- etc -. of the type are connected respectively to the second terminal of the third resistor, the power rail and the collector of the second p10 pn type transistor, the base of which is connected to the cathode of the first diode and through the fourth resistor is connected to the emitter of the second transistor, the anode of the first diode is connected to the first terminal of the first resistor and ka15 by the method of the second diode, the anode of which is connected to the collector of the first transistor and through the fifth resistor is connected to the base of the third transistor, the collector of which is connected to the base of the integrating transistor. the first capacitor plate and the first terminal of the sixth resistor, the second terminal of which is connected through the variable resistor to the power bus, the emitter of the integrating transistor is connected to a common 25 bus, the collector of the integrating transistor is connected to the second plate of the capacitor and through the seventh resistor is connected to the emitter of the second transistor, the second terminal of the first a resistor is connected to the anode of the third diode, the cathode of which is connected to a common bus. Compiled by V. Yakimov Editor O. Golovach Tehred M. Morgenthal Corrector M. Kucheryavaya Order 2135 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.