SU438124A1 - Variable Frequency Pulse Counter - Google Patents

Description

one

The invention relates to devices of pulsed technology and can be used in radio equipment and automatic control and monitoring devices as a pulse series counter.

Devices for counting pulses with a short automatic reset time are known, which are carried out with the aid of discharge trigger devices, which are self-excited relaxation schemes on active elements or on devices with a falling characteristic.

The disadvantage of these devices is that the time interval between the moment of arrival of a series of pulses and the time of operation of the device depends on the pulse frequency in the series, which is due to the method of switching on the storage and auxiliary capacitors relative to the trigger device. This disadvantage limits the applicability of such devices in systems requiring temporary stability.

The purpose of the invention is to improve temporal stability.

This goal is achieved by the fact that the proposed device, the output of the standby multivibrator through time sets the RC circuit connected to the base of the transistor switch, the collector of which is connected to the input of the threshold device and through a parallel diode and resistor to the storage capacitor.

The drawing shows the scheme of the proposed pulse train counter with a variable follow frequency.

The circuit includes a standby multI (Vibrator on transistors 1-3, limiting resistor 4, time specifying an RC circuit 5, 6, a resistor 7 in the collector circuit of a transistor switch 8, a resistor 9, a shunt diode 10, a storage capacitor 11 and a threshold device on transistors 12 and 13.

The pulses of positive polarity, coming to the input of the counter, are normalized in amplitude and duration by the waiting multivibrator on transistors 1-3. After starting the standby multivibrator, the capacitor 5 charges through the resistor 4 and closes the transistor switch 8 and the time determined by the parameters of the normalized pulse and the time determined by the parameters of the driving circuit 5, 6 and equal to the interval between the falling edge of the previous and the leading edge of the subsequent pulses coming from the waiting multivibrator . A subsequent pulse opens the transistor switch, and the process repeats. In the absence of a subsequent pulse, this time is equal to the period between two consecutive impulses, going with the lowest possible frequency, minus the relaxation time of the waiting multivibrator.

At time intervals corresponding to the closed state of the transistor switch, the storage capacitor is charged, 11 through a resistor 7 and a diode 10 connected in the right direction. Upon completion of a predetermined number of cycles, the voltage on the collector of the transistor-switch reaches the actuation level (Threshold device in transistors 12 and 13. Resistor 9 serves to discharge the storage capacitor 11 of a fire to skip pulses in the series or terminate them.

Thus, the moment of the counter actuation relative to the beginning of the arrival of the input pulses of an ephedel Egc is only a constant time circuit containing a storage capacitor 11 and a resistor 7 in the collector circuit of the tracing key 8, and does not depend on

the frequency of the incoming incoming pulses.

Subject of invention

A pulse train counter with a.-Variable repetition rate, containing a pending multi-selector, capacitor capacitor,

a transistor switch, a diode that drives an RC-iuenb and a threshold device, which differs from the fact that, in order to improve temporary stability, the output of the waiting multivibrator through the time setting iRC-CBb is connected to the base of the transistor switch, the collector of which is connected to the input a threshold device and a parallel diode and a resistor to the storage capacitor.