SU843171A1 - Pulse shaper - Google Patents

Description

S54) SHShULS FORMER

I

The invention relates to computing and pulse technology and can be used in devices of discrete automation.

A device for generating pulses used in discrete automation and in pulse devices is known, which contains an I-NB element, a diode, a capacitor, P}.

A disadvantage of this device is that to start it, it is necessary to generate pulses of a certain duration, i.e. the trigger pulse must be either shorter or longer in time by the pulse generated by the body.

The closest technical solution to the present invention is a pulse shaper, which contains a shaping unit, a trigger, two inverters and an additional NAND element, with one trigger input connected to the input bus and through the first inverter connected to one input of the additional NAND element, the other input of which is connected to the output bus, and the output through the second .inverter is connected to another input of the trigger, the output of which is connected to the input of block 2J

A disadvantage of the known pulse former is the false triggering with short impulse noise.

The purpose of the invention is to improve noise immunity by eliminating false alarms with short impulse noise.

The goal is achieved by the fact that a pulse shaper containing a forming unit has two inverters, an NAND element, a trigger, one input of which is connected to the input bus and through the first inverter is connected to one input of the NAND element, the other input of which is connected to the output bus, and the output through the second inverter is connected to the other trigger input, you are 384317

the stroke of which is connected to the input of the shaping unit, an additional shaping unit, a trigger, a logic element I, and an input bus connected to the input of the additional shaping unit, are introduced to the first input of the logic element I, with the first., additional trigger input, the second input of which is connected to the output additional block forming JQ and the second input of the logical element And, the third input of which is connected to the output of the additional trigger, and the output of the logical element And is connected to the input of the first inverter.

FIG. 1 shows a block diagram of a pulse former; in fig. 2 - timing charts of the device.

The pulse shaper consists of a formation block 5, an additional 20 formation block 2, triggers 3 and 4, inverters 5 and 6, an AND-NE element 7, an AND 8 element, an input bus 9, an output bus 1 O.

The operation of the proposed formation device 25 is considered for three possible cases.

1. An input pulse is applied to the input bus 9, the duration of which is longer than the pulse duration formed by the formation unit 1.

2. On the input bus 9 is supplied im-. trigger pulse, the duration of which is shorter than the duration of the pulse generated by the unit 5 for forming imz5 pulses, but greater than the duration of the pulse generated by the additional formation unit 2. ,

3-. A start pulse is applied to the input bus 9, the duration of which 40 is less than the duration of the pulse generated by the additional formation unit 2.

Initial state: at the input bus 9, logical b, at the output of trigger 45, 4 — logical O, at the output of element 8 — logical O.

1. Timing diagrams of the operation of the pulse shaping device. depicted in FIG. 2a ,50

At time t, a positive triggering pulse arrives at the input bus 9, at the output of the additional block 2, a pulse O appears, which closes the element AND 8 for the duration of the imp / duration formed by the additional formation block 2, the logical 14

The cue from the output of block 2 enters the input of trigger 4, the output of which appears logical 1. At the end of the pulse generated by the additional block 2 (time t ,,), the output of element And 8 appears logical 1, since all inputs of the element And 8 logical 1.

Logical 1 at the output of the element And 8 starts the block I formation, which forms a pulse (time) on the output bus 10,. the duration of which does not depend on the duration of the pulse at its input. At the end of the triggering pulse, on the input awl 9 (time C) trigger 4 returns to the initial state, i.e. a logical O appears at the output of the crygrieger 4, since a logical O is input at its input. Thus, a pulse at the output of the formation unit 1 appears with a delay of time equal to the duration of the pulse generated by the additional unit 2.

2. Timing diagrams of the pulse shaper are shown in FIG. 26

The operation of the circuit in this case does not differ from the first case.

The output element And 8 receives a pulse, the duration of which is equal to the difference between the durations of the triggering pulse and the pulse generated by the additional unit 2 (time -tg-1) - Logic 1 at the output of the element And 8 starts the unit 1, which forms a pulse on the output bus 10 which is determined by the parameters of the formation unit 1 and does not depend on the pulse duration at its input. The impulse on the output bus 10 appears with a delay of time equal to the duration formed by the additional unit 2 (time t, -tg ..

3. The timing diagrams of the pulse shaper are shown in FIG. 2c.

At time tg, an input pulse arrives at the input bus 9 of the additional unit 2. At its output, a logical O appears, which closes the element AND 8. A logical O from the output of an additional block 2 enters the trigger 4, its translation into a logical 1 state.

At the end of the start-up impulse, logical 1 appears at the input bus 9 at the output of block 2. Trig58

rep A returns to its original state, i.e. a logical O appears at its output. At the output of the element AND, the state does not change, since at least one logical O is always present at its inputs. During the entire time of the starting pulse, the start of block I does not occur. I Thus, when a triggering pulse arrives on the input bar 9, the duration of which is less than the duration of the pulse generated by the additional unit 2, the launch of unit 1 does not occur.

In the proposed former, noise immunity is increased by eliminating false alarms on triggering pulses, the duration of which is less than the duration of the pulse generated by the additional shaping unit. :

Claims (2)

The proposed tcoB pulse shaper can register pulses with a duration of more than the duration of the pulse of an additional form of a boat, i.e. make a selection of pulses in duration, which also expands its scope. Invention Formula A pulse shaper containing a forming unit, two inverters. NAND element, trigger, one input is connected to the input bus and through the first inverter is connected to one input of the NAND element, whose other input is connected to the upstream bus, and output via the second inverter is connected to another trigger input, the output of which is connected to the input of the shaping unit, so that, in order to improve the noise immunity, an additional shaping unit, a trigger, a logic element AND are inputted into it, and the input bus is connected to the input of the additional shaping unit, ci first logical input Whose element is And, with the first input of the additional trigger, the second. the input of which is connected to the output of the additional unit, the formation and the second input of the logic element I, the third input of which is connected to the output of the additional trigger, and the output of the logic element I connected to the input of the first inverter. Sources of information taken into account in the examination .one. USSR Author's Certificate No. 415782, cl. H 03 K 3/02, 12.01.72. 2. USSR author's certificate number 566311, cl. H 03 K 3/02, 09.03.76. 1