SU366419A1 - DIGITAL PHASOMETER WITH CONSTANT MEASUREMENT - Google Patents

Description

one

The invention relates to radio metering technology.

Digital phase meters with a constant measuring time are known, containing forming devices associated with a trigger, the output of which is connected to the counter through d, after the successively connected coincidence circuits with the counter, and through an automatic circuit with a frequency divider. Also, the trigger output through the first Matching circuit, the driver and the master oscillator is connected to the search circuit. In addition, the phase meter contains a multiplier connected to its second input.

However, the use of phase shifters with a synchronous motor significantly increases the measurement time due to low / high: the maximum rotational speed of the phases of modern rasteners, such as inductive or capacitive tin, and the presence of an amplifier in the synchronous motor drive circuit complicates the design and structural relationships.

The purpose of the invention is to increase the speed and simplify the apparatus.

This is achieved by supplying the phase meter with a mixer connected to one input with a multiplier, and the second to a master oscillator. The output of the mixer is associated with a search circuit and a phase automatic circuit.

the frequency control (PLL) of the master oscillator, consisting of a series-connected phase detector and a low-pass filter. Moreover, a frequency divider is connected to the second input of the phase detector through a second filter, the input of which is connected to the output of the multiplier.

In the drawing, the block diagram of the proposed phase meter is shown.

It consists of forming devices / q 2, trigger 3, cascades 4} 5 matches, master oscillator 6 and driver 7. Phase meter also contains automatic circuit 8, counter 9, multiplier W and mixer //.

In addition, there are phase detector 12, divider 13, filters 14 and 15 and search circuit 16.

Phase meter works as follows. The input oscillations, between which the phase shift is measured, are fed to the inputs of the devices Y and 2, respectively, in which the input oscillations are reconstructed in a sequence of pointed nmnulses corresponding to zero crossings (for example, at the beginning of the positive half period), and arrive at the trigger 5. The output pulses of the trigger, the duration of which is proportional to the phase difference between the input oscillations, are controlled by cascade 4, in the second

) the input of which receives pulses with a frequency

generator 6 through the driver 7. From the output of the cascade 4, the bursts of pulses arrive at cascade 5 controlled by the circuit 8. The number of pulses at the output of the cascade 5, transmitted to the output phase, is counted by the counter 9, which has a visual display.

Simultaneously, the input oscillations and / s from one of the inputs of the shaping devices are fed to an NC 3 multiplier with a multiplier. In this case, the signal with the frequency n / o goes to one of the mixer inputs}, to the second input of which oscillations of the generator 5 / zg are received. The lambda of the difference frequency LD equal (p / s - / zg) is fed to one of the inputs of the detector 12 of the circuit (PLL). To the second input of the detector, post-oscillation from the output of the divider 13 through the filter 14 of the first harmonic. Scheme 16 produces a gradual frequency tuning of the generator 6 until the difference frequency at the mixer output // is equal to the oscillation frequency of divider 13. After that, the PLL circuit is captured, circuit 16 is turned off, and generator 6 is controlled from the output of the detector 13 through the filter / 5.

The start of circuit 8, which determines the measurement time, is produced by the impulses from the output of divider 13, the frequency of which is 36 10, where k is a positive integer less than the frequency at the output of multiplier 10, which is ensured by connecting divider 13 to the output of multiplier 10. cases with

In order to simplify the equipment, the divider 13 is connected to the input of the multiplier 10.

Subject invention

Claims (2)

1. A digital phase meter with a constant measuring time, containing input devices that are connected to a trigger, the output of which is connected to a counter through two successively connected coincidence circuits and through an automatic circuit with a frequency divider, as well as through the first coincidence circuit a generator with a search circuit, a multiplier connected to the second input of the phase meter, characterized in that, in order to increase speed and simplify the equipment, the phase meter is equipped with a mixer connected by one input ohm to a multiplier, the second - a master oscillator, and an output of the mixer is coupled to the search circuit and the circuit; a phase automatic frequency control (PLL) master oscillator consisting of a serially connected phase detector and a low-pass filter, the frequency divider connected to the output of the multiplier connected to the second input of the phase detector. 2. A digital phase meter with a constant measurement time according to claim 1, characterized in that, in order to simplify the equipment, the input of a frequency divider connected to the automation circuit and the PLL circuit is connected to the multiplier input.