SU611176A2 - Threshold device - Google Patents

Description

one

The invention relates to a pulse technique and can be used to control the frequency of an alternating current.

According to the main author. St. No. 457967 a threshold device is known, which contains a relaxation RC generator, parallel to the input of which a thyristor is turned on, and a peak detector with an executive relay output (I.

The known threshold device does not allow to determine the position of the monitored point relative to the boundary frequency, which significantly limits its scope, since in a number of cases 1 it is necessary to know not only that the controlled frequency is higher (lower) than the boundary frequency, but also to have information about the removal of the co-controlled frequency from frequency limit value.

The availability of such information allows precautionary measures to be taken to prevent corruption. transition of controlled frequency through the limit value.

The aim of the invention is to expand the functional capabilities of the device.

To do this, a current sensor is inserted into the proposed device; it is connected to the thyristor power circuit and an additional peak detector connected to its output.

The drawing shows a schematic diagram of the proposed device.

The device contains a relaxation generator I, consisting of a resistor 2, a capacitor 3, a dynistor 4, a resistor 5, and a peak 5 detector b, consisting of a diode 7 and a capacitor 8, a thyristor 9, an executive relay 10, a current sensor P, an additional peak detector G2 consisting of a diode 13, a capacitor 14 and a resistor 15.

Limiting frequency fo

the threshold device is determined by the frequency of self-oscillations of the relaxation generator I. For the case. when the frequency of the monitored signal f-f is below the cut-off frequency fe, i.e. G 7o, the behavior works as follows. 15 When the supply voltage is switched on, the capacitor 3 begins to charge through the resistor 2. At the time when the voltage is reached on the voltage supply on the connected distor 4, the capacitor is quickly discharged through the distor and resistor 5, while a constant voltage is applied to the capacitor 8 of the peak detector 6 , under the action of which relay 10 is triggered, signaled by its contacts that f, fo At time 11, a signal pulse arrives that is triggered by frequencies.

At time 11, the capacitor 3 is discharged through the thyristor 9 and the current sensor I. The amplitude of the discharge current is determined by the magnitude of the difference T, - G0. On the additional capacitor 14 of the additional peak detector J2, a constant voltage is released (/ ", ,, equal to the amplitude of the pulsed operating current through the current sensor It. If at the time t the fit frequency is decreased, i.e. the difference T Those increases, which in turn will lead to an increase in the amplitude of the pulses passing through the current sensor II, and an increase in the DC voltage (/ ,.

Thus, the current sensor 11 of the additional peak detector 12 is inserted. obtain a constant voltage .1b, proportional to the difference 7i - TQ, and monitor the position of the frequency of the input signal f relative to the front frequency fo. At the time of the transition of the frequency of the monitored signal through the granular value, i.e. f, fe n G, Go, the voltage on the capacitor 3 does not reach (, dnistor 4, oscillations of the generator I break off and the contacts of the relay relay 10 open, thus signaling a transition controlled frequency through the boundary value, prn this (/, increases sharply, additionally signaling the transition f, through fe.

The introduction of a current sensor and an additional monitored detector provides information on the magnitude of the controlled frequency deviation from the boundary frequency, which, along with the implementation of tolerance control, measures the absolute value of the monitored frequency.

Claims (1)

Invention Formula Threshold device auth. CBD 457967, characterized in that, in order to expand 5 functionality, a current sensor is inserted in it, which is connected to the thyristor power circuit and an additional peak detector connected to its output. Sources of information taken into account prn examination: I. Copyright certificate № 457967, cl. O 05 V 1/03, 10.08.73.