SU646432A1 - Pulse train delay device - Google Patents

Description

(54) IMPULSE EXTENSION

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The invention relates to a pulse technique, can be used, in particular, to quickly convert short pulses into rectangular ones of greater duration with an amplitude equal to the maximum amplitude of the input pulses.

There are known devices for expansion of K pulses, containing an input differential amplifier, one of the inputs of which is supplied with an expandable signal, and the other with a feedback signal, charging a storage capacitor to a voltage equal to the input voltage 1. The output will become device monitors the input signal, poh & There is no external signal to switch the circuit to storage mode.

However, the known extenders can be used only for converting pulses that have a low-collapse turn or for pulses with a known temporal maximum position.

Closest to the proposed pulse extender containing an integrating chain, the input of which is connected to the input of the expander, and an output with a non-inverting input of the operational amplifier, to the output of which one of the accumulator capacitor plates, one output of the first switch and the output of the amplifier, the output of which is connected, are connected to the output of the diode with its inverting input and with the inverting input of the operational amplifier, and the control pulse generator, the output of which is connected to the control input of the first switch 2}.

The disadvantage of the device is low speed due to a long time restoring. This is due to the aggravation of the transient processes occurring at the moment of locking the first key, due to the delay of the signal in the feedback circuit and the inclusion of an element with oon-sided conductance.

The purpose of the invention is to increase the speed of the device.

The goal is achieved by the fact that a pulse expander containing an integrating chain, the input of which is connected to the input of the expander, and an output with a non-inverting input of an operational amplifier, connects one of the plates, ny6stenogog to the output through the diode. the capacitor, one output of the primary key and the input of its amplifier, the output of which is connected to its inverting input and the inverting input of the operational amplifier, and a generator of control modules, the output of which is connected to the control input of the first key, a voltage source, the second key which is connected between the non-inverting input of the operational amplifier and the connection point of the output of the source of the foam power supply to the second output of the first key, and the delay time that is connected between the output of the generator of secondary impulses pulses and the input control of a second key.

The drawing shows a structural scheme of the proposed emulator extender.

The output of the input operating voltage "lithium 1 through a semiconductor diode 2 is connected to a storage capacitor 3, the output of the first key 4 and the input of the output amplifier 5. The output of the latter is connected to an inverting amplifier of the operational amplifier. The second plate of the capacitor 3 is connected to the ground zero potential. Input expander through the integrating chain;

6c of a constant time shorter than the duration of the input pulses is connected to the non-inverting input of the operational amplifier 1 and the output of the switch 7, whose input is connected to the output of the voltage source 8. The control input of the switch 7 through the delay element

9 and the control input of the key 4 is connected to the output of the generator 10 control pulses. As keys 4 and

7, MOSFETs with high speed and small leakage in the closed state can be used.

The device works as follows. In the initial state, in the absence of VII of positive impulses at the output of the expander, a potential equal to the potential acting at its input is established by the action of the negative inverse. Keys 4 and 7 are locked. With the arrival of positive pulses at cxeJMy, the capacitor is charged by the output current of the operational amplifier 1, the voltage increasing at the capacitor is fed to the input of the output amplifier 5, and from its output to the inverting input of the operational amplifier 1, ensuring accurate tracking of the input voltage . When the signal decreases at the input of the expander, at the output of the amplifiers 1, a negative voltage arises, blocking the diode. The capacitor begins to discharge through its own leakage resistance, the input resistance of the amplifier 5 and the resistance of the closed switch 4 and diode 2.

The operation of the control pulse generator 10 is synphonized by an appropriate signal. Thus, keys 4 and 7 open with a delay relative to the input signal, determined by the required duration of the expanded pulse. When opening keys 4 and 7, the storage capacitor is quickly discharged, and the output of the expander due to the negative feedback sets the voltage equal to the voltage on the non-inverting input of the operational amplifier 1.

At the moment of closing the key 4, the voltage across the capacitor increases, as a result of which a negative voltage arises at the output of the operational amplifier, blocking the diode. Due to the delay element 9, the switch 7 closes with a delay relative to the switch 4. At the same time, the voltage at the non-inverting input of the operational amplifier increases to the initial potential with a speed determined by the constant discharge of the capacitor of the integrating chain 6. As a rule, the short pulse generators have a low output index, and the time constant of the integrating chain is small, and the input voltage is quickly restored at the input of the extender.

The voltage source 8 increases the discharge current of the storage capacitor, and, consequently, decreases its discharge. In case the positive pulses are supplied to the input of the expander at a certain constant level