RU74202U1 - DEVICE FOR MEASURING ELECTRICAL SIGNAL DELAY TIME IN FILTER - Google Patents

Abstract

The utility model relates to the field of radio engineering and is intended to measure the delay time of an electric, namely, harmonic signal in a filter. The device includes a first electronic key (1) and a filter (2) electrically connected separately from each other, and a second electronic key (3) with a frequency meter (4). In addition, the output of the filter (2) is also connected to the electronic key (3) with the possibility of its locking by the electric signal from the generator coming out of the filter from the generator (6). The device can be additionally equipped with an amplifier (5) between the filter (2) and the key (3). The device, simple and affordable to implement, will allow you to measure the transit time of the electrical signal through the filter in periods of its frequency. 1 s.p. f-ly, 1 ill.

Description

The utility model relates to the field of radio engineering and relates to measuring devices, devices and instruments in this area.

A device for measuring time is known, for example, a clock mechanism — an electronic type stopwatch with a quartz generator (see, for example, Polytechnical Dictionary, M-1980, Sovetskaya Encyclopedia Publishing House, p. 469).

However, it is impossible to measure the delay time of an electrical signal in an electromechanical filter by a known device.

It is a well-known method for calculating the delay time of any electrical signal, for example, in electrical circuits, by calculating empirically

t = S / V

where t is the delay time of the electrical signal or the propagation time of the electric current in the conductor;

S is the distance that an electric current passes;

V is the velocity of propagation of electric current in the conductor. (see, for example, IP Zherebtsov, “Electric and Magnetic Circuits,” Leningrad, 1982, p. 8).

An electromechanical filter (possibly some other four-terminal device) contains a mechanical resonant system in which there is a noticeable delay of the electrical signal, namely the harmonic signal, passing through the filter.

However, the authors are not aware of any means for measuring the delay time of the electric (harmonic) signal in the filter or the time it takes for the signal to pass through the filter, which are sufficiently quick and easy to read (size) to measure the delay time of the signal in the filter.

The purpose of the utility model is to create a simple device to provide the possibility of measuring the delay time of an electric, namely, harmonic signal in a filter, that is, a signal passing through it.

The problem is solved so that the device for measuring the delay time of the electrical signal in the filter contains installed at the input to

the filter is a first electronic key and a second electronic key and a frequency meter electrically connected with it, moreover, at the output, the filter is electrically connected to the second electronic key with the possibility of locking it by the output signal from the filter. In addition, the device is additionally equipped with an amplifier for the output signal from the filter installed between the output of the filter and the second electronic key.

The technical result achieved is expressed in the possibility of measuring the delay time of the electric (harmonic) signal in the filter, which was not previously carried out. The created device is simple and affordable to implement and implement, and thanks to the frequency meter, the delay time of the signal in the filter is expressed in periods of frequency passing through the filter. The result is easy to read and read.

The utility model is illustrated by the block diagram of the device.

The device includes a first electronic key 1 located at the entrance to the filter 2. The first electronic key 1 is also electrically connected to the second electronic key 3, to which, in turn, a frequency counter 4 is connected. In addition, the output of the filter 2 is connected to the second electronic key 3, but with the possibility of locking it with an output electric signal passing through the filter 2. Between the filter 2 and the key 3, an amplifier 5 can be additionally installed. The electric signal is received, for example, from the generator 6.

The device operates as follows.

An electric or sinusoidal harmonic signal from a generator has a frequency lying within the passband of an electric filter (e.g., electro-mechanical, quartz, piezoceramic), the signal delay in which must be measured, and the signal level corresponds to the acceptable for this filter.

The electrical signal from the generator 6 (see diagram) is fed to the first electronic key 1, which is opened, for example, by means of a mechanical switch (not shown in the diagram), and then to the input of the filter 2. At the same time, the signal is supplied through the open second electronic key 3, to the input of the frequency counter 4. Frequency counter 4, begins to count the periods of the frequency of the generator 6. At the same time, the signal transmitted through the filter 2 (output signal) is amplified (if necessary) by the amplifier 5 to a level at which the second electronic switch is reliably locked cha C and closes it. Thus, the frequency counter 4 will count the periods of the frequency of the generator 6, starting from the moment the signal arrives

to the input of the filter 2 and ending with the moment of its appearance at the output of the filter 2. This will be the delay time of the electrical signal in the filter 2 or the transit time of the electrical signal through the filter 2, expressed in periods of frequency passing through the filter 2.

The accuracy of the measurement depends on the speed of operation of the second electronic key 3, and, therefore, on the frequency properties of the transistors used in this key. To obtain higher accuracy of measurements, it is necessary to use higher frequency transistors in the second electronic key 3, respectively.

The proposed device allows you to simply, quickly and easily measure the delay time of the electric (harmonic) signal in electromechanical filters, using the data obtained for further, for example, theoretical, especially accurate calculations, and for calculations for necessary practical purposes and tasks. In addition, the device will allow, for example, to occasionally test various filters to assess the quality of their operability.

Claims (2)

1. A device for measuring the delay time of an electrical signal in a filter, comprising a first electronic key installed at the inlet of the filter and a second electronic key and a frequency meter electrically connected to it, the output filter being electrically connected to the second electronic key with the possibility of locking it by the output signal from the filter . 2. The device according to claim 1, characterized in that it is additionally equipped with an amplifier of the output signal from the filter installed between the output of the filter and the second electronic key.