SU834875A1 - Device for eliminating contact chatter - Google Patents

Description

(54) DEVICE TO ELIMINATE CONTACT DRAWS

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This invention relates to automated control systems and computing.

A device for eliminating contact bounce is known, which contains a trigger, an OR element, the output of which is connected to a counter, a sync pulse generator 1.

The closest to the present invention is a bounce device comprising a generator, a contact connected to one of the inputs of the OR element, a counter, the inverse output of which is connected to one of the inputs of the OR element, a counter, the inverse output of which. connected to one of the inputs of the element And, the output of which is connected to the counting input of the counter 2.

A disadvantage of the known devices is the low reliability and speed of operation.

The purpose of the invention is to increase the reliability and speed of work.

The goal is achieved by the fact that in a device for eliminating contact bounce, containing a generator, a contact connected to one of the inputs of the OR element, a counter, the inverse output of which is connected to one of the inputs of the element AND, the output

which is connected to the counting input of the counter, introduced a delay element, the input of which is connected to the output of the OR element and to the reset input of the counter, and the output is connected to the second input of the AND element, the third input of which is connected to the generator, and the second input of the OR element is connected to a common thickness . -

FIG. 1 shows a functional diagram of the proposed device; in fig. 2 time diagrams.

The device contains a contact 1, the output of which is connected to the element OR 2, the other input of which is connected to the common bus. The output of the element OR 2 is connected to the reset input of the counter 3 and through the delay element 4 (for example, an inverter) to the element 5, to the other inputs of which are connected the output of the generator 6 and the inverse output of the counter 3. The output of the element 5 is connected to the counting input of the counter 3. The device works as follows.

When you press once on pin 1, the sequence of signals arising as a result of bounce (Fig. 2a) through the OR element 2 (Fig. 2) and through the delay element 4 enters the input of the And 5 element, to the other inputs of which a pulse sequence is fed from the auto-oscillator 6 (Fig. 2c) and the signal from the inverse output of counter 3 (an asynchronous four-bit binary summing counter based on SK-triggers is used). When all the input elements of the AND signals are positive, a positive signal appears at its output (fig. 2d) which is fed to the counting input of counter 3 and is written to its first trigger, since the negative input signal from the element OR is present at the reset input of counter 3 2. Since, as a result of the chatter between each pulse at the output of contact 1, the input of the element OR 2 is rejected, then in this gap, the element OR 2 works as an inverter, inverts the negative signal of its second input a, resulting in a positive signal at the reset input of counter 3, which, after each recorded pulse, resets counter 3 to the initial state. In the same interval, the input of the element And 5 using the element 4 of the delay receives a negative signal of the ban. The above process takes place during the whole bounce of contact. Upon the final closure of pin 1, the inputs / element 5 have positive signals, it triggers and repeats the sequence of generator pulses 6, which arrive at the counting input of counter 3 and are counted because there is a negative enable signal at the reset input. By plugging the sensor 3, a positive signal arises at its direct output (Fig. 2 (), which is sent to other devices, and a negative signal at the inverse output blocks And 5).

b.

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Claims (2)

FIG. 1 By opening contact 1, the counter 3 is reset, since a positive signal is received from the OR 2 element at the reset input. The device returns to its original state and is ready for further operation. The proposed device is made on the integral elements, can serve an unlimited number of contacts, increases the reliability and speed of the circuit and completely eliminates the phenomenon of chatter. Claim device A device for eliminating contact bounce, comprising a generator, a contact connected to one of the inputs of an OR element, a counter whose inverse output is connected to one of the inputs of an AND element whose output is connected to a counter input of the counter, in order to increase reliability and speed of operation, a delay element is inserted in it, the input of which is connected to the output of the OR element and to the reset input of the counter, and the output is the second input of the AND element, the third input of which is connected to the generator, and the second the input element OR is connected to our bus. Sources of information taken into account in the examination 1. USSR author's certificate in application number 2570829/21, 18.01.78. 2. Il'in G.I. Korolkov, K.M. A device for suppressing the influence of bounce of electromechanical contacts in impulse control systems. Kiev, Publishing House of the Academy of Sciences of the Ukrainian SSR, 1978, p. 23, fig. 14 a. mm & t oshpppppppppppppppp at and and pisza -e-g  g d.2