SU385235A1 - CONDENSING FREQUENCY - Google Patents

Description

I

The invention relates to the field of electrical measuring equipment and can be used to create capacitor often meters of your neck.

Known capacitor frequency meters containing a stable source of constant voltage, a key element, a capacitance, a full-wave pull-out magnetic magnetically measuring measuring device, have a low sensitivity due to the incomplete use of energy from a stable constant-voltage drain.

The purpose of the disclosure is to increase the sensitivity without increasing the magnitude of the source or capacitor capacitance.

This goal is achieved by the fact that the frequency meter is equipped with a phase inverter and an additional key element, the control electrode of which is connected to the source of the measured frequency signal through the phases of the inverter and one of the output electrodes to the opposite apex of the bridge circuit of the two-half-half-star.

The drawing shows the block diagram of the proposed frequency. O, n contains, it is a stable source of constant voltage /, key transistor elements 2 and 3, resistors 4 and 5, transistor phase inverter 6 with a resistor in the collector circuit 7, a magnetoelectric device 8 included in the diagonal MOCTOBoii of circuit 9, a capacitor 10, resistors 11 1 and 12 connected to the bases of the transistors 3 and 6 and input terminals 13 for connecting the source of the signal of the measured frequency.

Frequency meter works as follows.

The test voltage is applied to the clips 13. Its amplitude should not over time exceed the response rate of the key elements.

Let the INPUT signal translate the key elements into | Mk; this state.

At the same time, the bases of the three-way transistors 3 and 6 should be applied | Vats negative but relate to the emitters at the voltage. Resistors 11 and 12 limit and equalize the currents through the base-emitter junction of transistors 3 and 6.

IF the transistor 6 is open, then the base of the transistor 2 relative to the emitter is not noticeable. The threshold is low, and it is closed. The capacitor 10. Is charged up to a voltage equal to the source's location, according to the following: negative pole of source 1, resistor 4, rectifier bridge circuit I, magnetic transistor 3,. Positive source voltage H0v. The capacitor plate connected to the collector of the transistor 3 has

sholozh.nenyyy in terms of “opposite facing potential”.

When the voltage across the terminals 13 is varied, the transistors 3-6 are closed, the transistor 2 is open. The co-capacitor 10 is recharged in the following circuit: the positive source, the i / /, the open transistor 2, the optical bridge, the schema 9, the magnetoelectric device 8, the reoistor 5, the negative zero, and, sochpi, ka /. The plate of the capacitor 10 connected to the 1 st collector ;; stor 3, the negative potential of the opposite side of the lining is numb. Thus, for one half-cycle of the voltage to be measured, transistor 3 must be closed, transistor 2 is open, and in the next ooperiod period: transistor 3 is open, TpaiHSHCTOp 2 is closed. This is achieved by the fact that the base of the transistor 2 is connected to the voltage source of the measured frequency through a phase inverter, the role of which is played by transistor 6 with resistor 7. If transistor 6 is open, then transistor 2 is also closed on Turn.

The deviation of the indicator of the magnetoelectric device 8 is pro-cyanically to the average current flowing through it. The average current of the measured frequency, the capacitance a of the capacitor 10 and the voltage of the source is 1.

Nearby the capacitor is recharged in one half-period from the voltage of the stable source to the same polarity, then the same polarity, then

The average TCIX through instrument 8 will be twice

; more than in the known frequency meters.

The subject is invented and I

 A capacitor frequency meter containing a stable source of constant nanr: the same; the KEY element, whose control electrode is connected to the signal source measuring its own frequency, and one of

Electrodes - to the lining of a capacitor of a fixed capacitance, bottom | zero; a periodic top; a simulator made but a bridge circuit; the diagonal of which includes a magnetoelectric measuring device; one of the vertices of the BRIDGE circuit is connected to another plate of the fused capacitor , characterized in that, in order to increase sensitivity, it is equipped with a phase inverter and an additional key element, the control electrode of which through a phase inverter is connected to the source of the measured frequency signal, and one of the output signals ktrodov - protivoiolozh.noy to the top of the bridge circuit.