SU1265980A1 - Device for eliminating effects of contact chattering - Google Patents

Abstract

The invention can be used for remote control of measuring and electronic computing devices. The purpose of the invention is to increase the speed and reliability of the device. The device contains remotely remote mechanical contact I, RS-trigger 3 and bus 2, 4, 5 and 11 of the control voltage source, output and power. To achieve this goal, resistors 6, 7, and 8, capacitors 12 and 13, AND-HE elements 8 and 9, and inverter 14 are introduced into the device to form new connections between the elements of the device. 2 Il.

Description

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The invention relates to a pulse technique and can be used for remote control of measuring and electronic computing devices.

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

The device contains a remotely remote mechanical contact 1, the common output of which is connected to the bus 2 of the control voltage source, RS-flip-flop 3, output voltages 4 and 5, resistors 6-8, I-HE elements 9 and 10, power supply 11, capacitors 12 and 13 and the inverter 14. The single and zero outputs of the RS flip-flop 3 are connected respectively to the output terminals 4 and 5 and the resistors 6 and 7, the second terminals of the resistors are connected respectively to the second inputs of the AND-NES elements and the plates of the capacitors 12 and 13. Other plates capacitors connected to common tine. The first inputs of the elements AND-NOT 9 and 10 are connected to a common bus. The first inputs of the AND-HE elements 9 and 10 are connected to the mechanical contact I and through the resistor 8 to the power supply bar 11. The output of the element AND-NOT 9 is connected to the single input of the RS flip-flop 3, and the output of the element IS-NOT 10 - to the bullet input of the RS-flip-flop 3.

Device d, l eliminate contact bounce works as follows.

When the power is turned on, the device is always reset. If, when the power is turned on, a single output of the RS flip-flop 3 appears instead of the zero logic level, the charge of the capacitor 13 starts, and after the full charge of the capacitor 13 is over, the time determined by the parameters of the resistor 7 and the capacitor 13 the input element AND-NOT 10 reaches a single logical level. The zero logic level detected at the output of the NAND 10 element, arriving at the zero input of the RS flip-flop 3, establishes a single logic level at its zero output and a zero level at the single output. The circuit is reset. Start} 1 the charge of the capacitor 12 through the resistor 6 and the discharge of the capacitor 13 is charged. After the discharge of the capacitor 13 to the zero level, the RS1 trigger 3 is kept in the initial state by single logic levels at the single and zero inputs.

When the remote mechanical contact 1 is opened for the first time (Fig. 2a), a single logic level is established at the first input of the NAND 9 element from the power bus 11 and the resistor 8, which together with the single level forms the RS flip-flop 3 at the single input the zero logic level, the triggering RS-flip-flop 3. At its single output is set to a single level, and at the zero bullet logic level (Fig. 26). Subsequent contact bounce when the mechanical is open

contact 1 does not cause the RS-flip-flop 3 to return to the initial state, since at the zero input of the RS-flip-flop 3 a logical level is maintained first with a zero level at the second input of the AND-NO element 10 (the charging time of the capacitor 13 to a single logic level is greater than the maximum bounce time of mechanical contact 1), and at the end of bounce - a steady-state unit level at its first input (mechanical contact 1 is completely open).

The first time the mechanical contact 1 closes, the zero level coming from the bus 2 of the control voltage source at the output of the NAND element 10 forms a zero logic level, which, affecting the zero input of the RS flip-flop 3, sets the RS-flip-flop 3 at the zero output and the output bus 5 is a single logical level, and at the unit output and the output bus 4 is a zero logic level (FIG. 26). The subsequent contact bounce when the mechanical switch 1 is closed does not cause a new RS-flip-flop 3 to tilt, because the single input of the RS-flip-flop 3 maintains a prohibiting unit level first with a zero level at the second input of the AND-HE element 9 (the charging time of the capacitor 12 to a single logical The level is chosen to be greater than the maximum bounce time of the mechanical contact 1), and at the end of the bounce, it is set to the zero logic level at its first input (mechanical contact 1 is completely closed). The circuit is reset.

Claims (1)

Invention Formula A device for eliminating the influence of contact bounce, comprising a mechanical contact, an RS flip-flop, a power supply bus and a common bus, the single and zero outputs of the RS flip-flop being connected to the output bus. Mi, characterized in that, in order to increase speed and reliability, It includes three resistors, two capacitors, an inverter and two NAND devices, the first input of one of which is connected directly, and the second through the inverter to the first output of the mechanical contact and through the first resistor to the power bus, the second input of the first electric The IS-NOT is connected via the first capacitor to the common bus and through the second resistor to the zero output of the RS flip-flop, the second input of the second element IS-NOT is connected via the second capacitor to the common bus and through the third resistor to the single output of the RS flip-flop, the output of the first element IS-NOT is connected to the unit input of the RS flip-flop, and the output of the second element IS-NOT is connected to the zero input of the RS-flip-flop, while the second output of the mechanical contact is connected to the control voltage source bus.