SU1309261A1 - Generator of pulses with programmable pulse period-to-pulse duration ratio - Google Patents

Abstract

The invention is intended for control systems and digital software control of electric welding equipment and can be used in control systems and automatic control of various technological processes, as well as in computing and measuring devices. The aim of the invention is to expand the functionality by providing a programmable change in the duty cycle at a constant pulse duration, as well as increasing the temperature stability. To achieve this goal, a current-limiting buffer element 6 with three states, code resistors 7, code buffer elements 8 with three states, and elements OR 9 are added to the device. The device also contains HE I and 2, capacitor 3, resistors 4, 5, bus 10 control. Higher temperature stability is achieved due to the fact that the recharging of the capacitor 3 is carried out through the elements, which have a high temperature stability. 1 il. with S (L SO o soy O5

Description

The invention relates to a pulse technique, is intended for control and digital systems of control welding equipment and can be used in control systems and automatic control of various technological processes, as well as in computing and measuring devices.

The aim of the invention is to extend the functionality by providing a programmable variation in the duty cycle at constant

the duration of the pulses, as well as increase (5 output of the buffer element 6 is disabled

the temperature stability of work is improved by improving the temperature stabilization of the duration and frequency of the generator pulses.

The drawing shows a functional diagram of the pulse generator. With a programmable duty cycle.

The generator contains the first 1 and second 2 elements, the NOT, the capacitor 3, the resistor 4, the current limiting resistor 5, the current limiting buffer element 6 with three states, the code resistors 7, the code buffer elements 8 with three states, the elements OR 9 and the bus 10 management The output of the element 1 is connected to the input of the element 2 and to the information input of the current-limiting buffer element 6, and the output of the element 2 through the series-connected capacitor 3 and resistor 4 is connected to the input of the element 1, and the output of the element 2 is connected to the control input of the current-limiting buffer element 6. One output of the current-limiting resistor 5 is connected to the common point of the capacitor 3 and the resistor 4, and its second output is connected to the output of the current-limiting buffer element 6. Some terminals of the code resistors 7 are connected to each other and to the common point of the capacitor 3 and resistor 4, and their other terminals are connected to the outputs of the code buffer elements 8. The information inputs of the buffer elements 8 are connected to the common point of the device, and the control inputs are connected to the outputs of the OR elements 9 , one inputs of which are connected to the output of the first element NOT 1, and others with control buses 10 which are supplied with digital program codes, for example, from microprocess

the weed system that sets the time parameters of the pulse sequence: - no.

The generator works as follows.

At the moment of switching on the supply voltage, the capacitor 3 is discharged. Assume that the output of the element is NOT 2, the voltage is Е (В - power supply voltage of NOT elements and buffer elements), then NO 1 voltage is applied at its input and output element,

but

and on the input element is NOT 1

voltage is 1. In this case

from the current limiting resistor 5 (the output of element 6 is in the high- impedance state, since from the output of the element HE 2 to the control

the input of the buffer element 6 enters the logical 1) and the capacitor 3 begins to be charged with a high level of the output voltage of the element 2 only through the included code resistors 7 and the outputs of some (only having voltage levels equal to O) of the code buffer elements B, the code buffer element 8 has at the output oh if on his control

the input is O. If the control input of the buffer element is B 1, then the output of element 8 goes into a high impedance state, i.e. disconnects from code resistor 7,

Thus, the total amount of conductivity: code resistors 7, and hence the charging time of capacitor 3, can be changed programmatically by changing the code at the inputs of the elements OR 9, which is transmitted through these elements to the control inputs of the buffer elements 8.

As the capacitor 3 charges, the voltage across the resistor 4 and the input element NO 1 falls. As soon as this voltage reaches the operation threshold of the HE 1 element, it closes and at its output the voltage becomes Q equal to 1, and the output of the HE element 2 equals O. From the output of the HE element 1, a high level voltage equal to i goes to the inputs elements of IPI 9 and disables all code reductions; tori 7 from the outputs of the code buffer elements 8, transfer via the elements OR 9 outputs of all elements 8 to a high impedance state. In addition, from the output element is NOT level

 3 1, the voltage equal to, goes to the information input of the current-limiting buffer element 6 and is transmitted to its output, since a low voltage level, equal O, coming from the output of the HE element 2 to the control input of the buffer element 6 transfers the latter to information transfer mode from the information input to the output.

The voltage at the common point of the capacitor 3 and resistor 4 abruptly changes sign and becomes negative, approximately equal to b. The capacitor 3 is recharged by the output voltage of the high level of the limiting buffer element 6 through the current limiting resistor 5 and the output of the NOT element 2. During the recharging of the capacitor 3, the voltage at the common point of the capacitor 3 and resistor 4, as well as at the input of the element NO 1 is growing. As soon as it reaches the operation threshold of the HE I element, it opens and at its output the voltage becomes O, which causes a change in the state of the HE element 2, at the output of which a voltage equal to 1 appears, and at the common point of the capacitor 3 and resistor 4, the voltage jump changes to the level of E + and (where Up is the voltage of the response threshold of the element NO 1). The process of capacitor 3 recharging is repeated by the output voltage of the HE 2 element through some code resistors 7 and the outputs of some code buffer elements 8. The generator signals can be removed from the output of the HE 1 element or from the output of the HE 2 element

The duration of the pulses at the output of the element is NOT 1 - the value is equal to and approximately equal to

С „, 0,7 CR5, (1)

where Tn1 is the pulse duration, s;

C - capacitor capacitance 3, F; RJ- - resistance of the current-limiting resistor 5, Ohm,

The duration of the pauses at the output of the element NOT 1 is determined by the value of the capacitance of the capacitor 3, the total conductivity of the included code resistors 7 (dependent on the code on the generator buses 10) and is equal to

O., (2) Zp

Sp1- duration of pauses, s; G, - capacitor capacitance 3, F;

 P1

1 De

21 p total conductivity of the included code resistor 7, Ohm-.

Total Conducted. included code resistors 7 is calculated from

(3)

where a.

R7, 2

Of

,,., and | - are equal to O or 1, in

depending on the code on the tires 1 O generator (inputs of elements OR 9); , R - - resistance code resistors 7, Ohm,

Ratios (I) - (3) is water, which changes the software code on tires 10, gets at the output of the element NOT 1 a programmatically variable pause duration at a constant pulse duration, while the duty cycle is equal to

 Gsh. .

T-- R7tT

To exit an NOT 2 item, the programmable value is the duration of the pulses with constant pauses between them. The duty cycle of the pulses at the output of element 2 is equal to the ratio

P1

  .(five)

In this pulse generator with

the programmed duty cycle, an increase in the temperature stabilization of the duration and frequency of the pulse following is achieved due to the fact that the capacitor recharges through the elements whose electrical parameters have a high temperature stability, there are no elements that introduce additional instability of a higher order.

Claims (1)

Invention Formula A pulse-width programmable pulse generator containing a series-connected two NO elements, a capacitor and a resistor, the other output of which is connected to the input of the first element NOT, and the common point of the capacitor and resistor is connected to the first output of the current-limiting resistor, I distinguish 5 13092616 by the fact that, in order to expand the function with three states, the input of the training opportunities and the povagania is connected to the output of someone who has the stability of the work, the output of the connected element is not : th buffer to the second output current-limiting element with three states, a resistor, the nerve terminal of which is soda resistors, code buffer. United through code resistors with three elements and code buffers elements from cops ШШ, the first entrances of which are from There are three states, the informational ones are connected to the control buses, and the second inputs of which are connected to the common point, are connected to the output of the first 10th device, and the control inputs of the element and the information input are connected to the outputs of the corresponding current-limiting buffer element OR.