SU138991A1 - Contactless device for receiving low frequency rectangular pulses - Google Patents

Description

Non-contact devices designed to produce low-frequency rectangular pulses are known and are based on the use of complex electronic circuits.

The proposed device is characterized in that it allows low-frequency rectangular pulses to be obtained by contactless means using simpler and more reliable equipment.

FIG. 1 is a schematic diagram of a six-phase device for receiving rectangular pulses; in fig. 2 .- form of voltage at the output of the selsyn; in fig. 3 - voltage form on secondary windings of transformers 7, 8, 9; in fig. 4 shows the voltage form at the output of the device.

As a low-frequency pulse sensor, selsyn C (Fig. 1) is used, which is powered by a high-frequency source and rotates at a speed corresponding to a low frequency. During the rotation of the selsyn, the voltage at its output has the form given in pa of FIG. 2

In the nonlinear block A on the resistors I, 2, 3, the voltage of the selsyn and the output voltage of the rectifying bridge 4 connected to the secondary winding 5 of the transformer is added.

The primary winding 6 of the transformer receives power from the AC network of increased frequency.

In addition, cutting off parts of sinusoids of the modulated selsin voltage less than a predetermined value occurs.

Transformers 7, 8, 9 increase the amplitude, and hence the steepness, of the output voltage of the nonlinear block A (Fig. 3).

Using a non-linear unit B (ring demodulator), rectangular voltage pulses are obtained under the condition that the voltage amplitude of the secondary windings 5 of the transformer is greater than the voltage amplitude f / 2 of the secondary windings of the transformer 10. The primary winding of the transformer 10 is connected to the high-frequency AC network .

The output rectifiers 10 cut off the negative voltage pulses, and the filters 12 filter out the higher frequency components.

At the output of the device, rectangular pulses of a low frequency voltage are given a predetermined width.

Subject invention

A contactless device for obtaining low-frequency rectangular pulses, characterized in that, in order to simplify the circuit and increase its reliability, it contains a selsin excited by an increased frequency current and rotated at a speed corresponding to the desired low frequency, a nonlinear block on semiconductor diodes for cutting parts , modulated voltage sine waves smaller than a given value and a ring demodulator that converts a series of sinusoidal pulses from a non-linear unit into square impulses Lses of a given width and amplitude.