SU449441A1 - Pulse selector for long and - Google Patents

Description

The invention relates to electronics, can be used in electronic and quasi-electronic PBX and cordless switches. Pulse selectors are known in duration, containing an AND circuit, connected to the Input Source by one input through the NOT circuit, and the other through a single vibrator. The purpose of the invention is to select pulses with a duration of both smaller and larger than the set value. It is achieved by the fact that the proposed selector contains an additional AND circuit connected by one input to the input source and the other through the NOT circuit to the one-oscillator output. Figure 1 shows the diagram of the selector; figure 2 - the timing diagram of his work. The pulse selector contains a one-shot one in duration, producing pulses of duration T, NOT circuits (inverters) 2, 3, circuits AND 4.5. Input 6 of the selector is connected to the input of the one-shot, to the input of the first circuit AND 4 and through the circuit NOT 2 to the input of the circuit AND 5. Output 7 of the one-vibration is connected to another input of the circuit AND 5 and through the gate 3 to the circuit And 4. Output 8 of the selector serves outputting a signal about the appearance at the input of the inverter 2 of a pulse of duration To the output 9 about the appearance at the input of the inverter 2 of a pulse of duration. The duration of the I / pulse of the waiting multivibrator is chosen from the ratio T t; , T where .. is the maximum duration of short input signals: and D) is the minimum duration of long analog signals, i The diagram of operation from the collector contains the following designations:

a - impulses entering the inverter 2 selector in succession

duration U I-j. L

.

(b) pulses with a duration of five months; produced by a single vibrator;

in - the signal at the bypass 8; g - output signal 9.

The selector works as follows

In the initial state, input 6 and output 7-9 contain zeros.

At input 6 receives a zero-pulse duration, for example, "In this case

through the inverter 2 to the input of the circuit And 5 flows zero; at the same time, the single-oscillator 1 is started, and a unit appears at its output 7, and zero arrives at the input of the circuit AND 4 through the inverter 3.

Thus, on outputs 8 and 9 there are zeros. After the one-shot operation finishes, a zero appears at its output 7, and a unit enters the circuit I input. As the input signal continues, both units of the AND 4 circuit have units, and output 8 indicates that there is a pulse with a duration of - (figure 2, position c).

Upon receipt at the input 6 of the selector short pulse With 5 t YAR. schemes similar to what is described. At the end of the input pulse, zero arrives at the selector input 6 and a unit enters through the inverter 2 at the input of circuit 5, the other input of which also contains one, since the one-shot continues to work (there is one at its output 7). At output 9, a signal of duration t -1 appears,

witness (sew on receipt at the input 6 of the selector of a short pulse.

The described selector can be used, for example, to distinguish between request and release pulses from telephone stations.

The subject of the invention 0

Pulse selector by duration, containing AND-connected circuit. to the input source by one J input through the NOT circuit, and by the other 5 via a one-shot, which differs in that, in order to select pulses with a Duration as

smaller and larger than the set value, it contains an additional AND circuit, connected by one input to the input source, and the other through the NOT circuit to the one-shot output.

2

R

to

ay

-h-,

at

 2