SU417887A1 - - Google Patents

Description

one

The invention relates to devices for tuning oscillatory circuits and can be used in the radio industry.

A device for adjusting oscillatory circuits is known, comprising a master oscillator, a phase discriminator, a static trigger, an electric motor reversing circuit, a reversible direct current electric motor, a controllable switch, and an electromagnet clutch that serves to break the electric motor shaft.

The use of a known device assumes that the adjusting elements, e.g. the trimmer cores of the inductors, in the whole batch of tuned circuits require the same force to rotate them. However, under production conditions, this is not always achievable, as a result of which there is a variation in the accuracy of adjustment of different circuits in one batch.

The purpose of the invention is to improve the accuracy of contour tuning.

This is achieved by the fact that the device contains a torque sensor on the shaft of the included electric motor, the output of which is connected to the control input of the controlled delay circuit, and the output of the delay circuit is connected to the winding of the electromagnetic clutch via a threshold device.

FIG. 1 shows the block diagram of the proposed device; in fig. Figure 2 shows one of the embodiments of a controlled delay circuit together with a torque sensor connected to its input.

The block diagram contains a generator 1, a configurable circuit 2, a phase discriminator 3, a static trigger 4 with a separate input, a threshold device 5, an electromagnetic clutch 6, a rectifier 7, an electric motor reversing circuit 8 consisting of a bridge amplifier, switch 9 (for example, through the relay contacts), the electric motor 10 is switched on, the torque sensor 11 on the shaft of the switched on motor, a control circuit 12 of the delay.

During the tuning of the circuit, due to the non-uniformity of its phase characteristic, signals in the form of differentiated pulses appear at one of the outputs of the phase discriminator and hold the static trigger in one of the stable states. In this case, the diagonally opposite shoulders of the bridge amplifier are opened, and a current arises in its diagonal, which, passing through the contacts of the controlled switch, ensures the rotation of the electric motor. The direction of rotation of the motor depends on the initial detuning of circuit 2 into that

or the other side of the frequency set on the generator.

FIG. 2 the following notation is accepted: 13 — charge-discharge bottom chain consisting of resistor 14 and capacitor 15; 16 — amplifier; 11 — torque sensor, in which resistor 17 is used, connected to the motor power supply circuit. The amplifier 16, together with the charging chain 13, form a controllable delay circuit 12.

When adjusting the circuit on the torque sensor, a voltage arises, the value of which depends on the magnitude of the torque on the shaft of the included electric motor. The signal from the output of the torque sensor, falling on the control input of the controlled delay circuit consisting of amplifier 16 and charge-discharge circuit 13, determines the amount of voltage up to which the capacitor 15 of the charge-discharge circuit is charged i.e., the magnitude of the signal at the output of the threshold device 5. The response threshold of this device is above the incoming voltage at its input.

The rotation of the motor shaft is transmitted through an electromagnetic clutch to the trimming element of the circuit, as a result of rotation of which the intrinsic frequency of the circuit approaches the set one. At the moment corresponding to the sensitivity threshold of the phase discriminator, pulses appear simultaneously on both of its outputs. In this case, trigger 4 is tilted at the frequency of incoming pulses. The signal from its outputs through the capacitors 18 and the rectifier 7 acts on a controllable switch that interrupts the motor power supply circuit. After that, the motor shaft continues to rotate by inertia and adjusts the circuit for some time, determined by delay circuit 12.

When the motor power is turned off, the charge-discharge circuit capacitor 15 is charged up to a voltage equal to the output voltage of the amplifier, determined by the voltage on the torque sensor. After turning off the power to the motor, the voltage on the torque sensor becomes zero, and the charge capacitor begins to charge from the source through the resistor 19 to the pickup voltage of the threshold device, upon reaching which a breakdown signal is applied to the coil of the electromagnetic clutch. Clutch breaks the motor shaft, and setting

contour is terminated.

Thus, the delay time between the moment when the motor is turned off, determined by the sensitivity threshold of the phase discriminator and the end of the loop setting, depends on the voltage value at the torque sensor.

For example, if a large force is required to rotate the loop trimmer, the voltage on the torque sensor is large, the amplifier transistor is open more and, accordingly, more time is required to charge the capacitor 15 during which the motor shaft rotates by inertia , adjusts the contour.

The application of the proposed device allows to reduce the variation in the accuracy of adjustment of various circuits.

Subject invention

A device for tuning oscillatory circuits containing tunable loop connected, phase discriminator, the second input of which is connected to the generator and the input of the adjustable loop, trigger, reversing circuit, controlled switch, control input of which through the rectifier and capacitors is connected to the reversing circuit inputs, electric motor and electromagnetic clutch, characterized in that, in order to increase the accuracy of setting the contours, the control input of the electromagnetic clutch is connected to an electric motor elem via a series connection

torque sensor, controlled delay circuit and threshold device.