SU951183A1 - Device for checking low frequency amplifiers - Google Patents

Description

The invention relates to techniques for measuring the parameters of a four-terminal network and can be used to control the parameters of low-frequency amplifiers (ULF) of electrophones, tape recorders, sound channels of television sets, etc. in the conditions of their mass production.

A device for controlling the parameters of four-terminal devices, in particular linear distortion of the ULF, containing signal generators, detectors, a gating device and a cathode ray tube (CRT) tl].

The disadvantages of this device are the inability to control all parameters of the ULF: nonlinear distortion, control of all noise, background, etc. and the lack of an integrated fitness indicator of a controlled ULF.

A device is also known for measuring the non-polarity of the amplitude-frequency characteristics, containing a noise generator connected to the controlled system, narrow-band filters connected in η parallel circuits with dispersion meters, comparing cells and linear indicators, combined into a single display panel (23.

The disadvantages of this device are the lack of an integrated estimation of the ULF parameters and the low productivity of control of the ⁵ ULF parameters under mass, production conditions, which is due to the formation and supply of different types of test signals to the ULF when measuring these ULF parameters, such as linear and nonlinear .. distortion, noise, background, etc.

The purpose of the invention is the reduction of control time.

._ The goal is achieved by the fact that in the device for monitoring low-frequency amplifiers, containing a recording unit, a test signal generating unit connected to one of the device inputs, the second input of which is connected to the inputs of η circuits, each of which consists of a series-connected bandpass filter , a rectifier and a comparing element, the second input of which is connected to a reference voltage source, η squares, N + 1 adders and N channels are introduced, each of which consists of m circuits connected in series of an analog filter θ, rectifier and quadrants, where N «1,2,3, etc. - the number of controlled parameters of the amplifier, a m = 1,2,3, etc., and η = 1,2,3, etc. - the number of frequency components selected for measuring each parameter, while the output of each comparing element in η circuits is connected through a quadrator to the corresponding inputs of the first and (Ν + 1) -th adders, and the second input of the device is connected to all inputs of N channels, the output of each quadrator in m circuits of N-1 channels of which is connected to the corresponding inputs of the adder in the (N-1) -om channel and to the corresponding inputs (N + 1) -ro p of the adder, and the output of the quadrator in m circuits of the Nth channel the corresponding input of the (N + 1) -ro adder and to the first input a recording unit, (N + 1) inputs of which are connected to the corresponding outputs (N + 1) of the adders.

The test signal generating unit is made in the form of a set of generators, the frequencies of which are distributed in the partial range of the controlled amplifier, and their values correspond to the values of the tuning frequencies η-x bandpass filters.

The drawing shows a structural diagram of a device. -

The device contains a block for generating a test signal 1, a controlled amplifier 2, η band-pass N filters 3, band-pass filters 4, rectifiers 5 and 6, (n + St) '1 = 4 squares 7, comparing elements 8, recording unit 9, N + 1 adders 10 - 12, indicators 13 and the inputs of the device 14 and 15. The recording unit 9 is a set of indicators 13 connected to adders 10 - 12. The indicators can also be connected directly to the squares 7 for monitoring the voltage of one frequency (t is 1 ), for example when measuring noise.

The indicators are made either in the form of gauges, light indicators, or in the form of a digital unit with the issuance of data for monitoring on a computer.

The device operates as follows: as follows.

The signal from the block forming the test signal 1 is fed to a controlled amplifier 2, the output of which the signal is fed to bandpass filters 3.

After narrow-band separation of the components by the filters 3, the signal passes through the rectifiers 5. The filtered components from the outputs of the rectifiers 5 are fed to the 'comparison elements 8, in which a comparison is made with a given reference voltage. The differential voltages from the outputs of the comparing elements are supplied to the nth quadrator 7, and then the first adder 11 and to the (N + 1) adder 10. At the same time, the signal from the output of the controlled amplifier 2 goes to the inputs of the filters 4, and then

S on rectifier 6 and 5 ¹ . n ¹ quadrators N ¹

7. From the outputs of $ 2 gp · quadrators 7 sig1 = 1 ^{1, the} cash also goes to N + 1, the sum N torr 10, and from squares 7 to

1 = 1 ¹ corresponding inputs (N-1) of the adders 12. The sum of all distortions is fed to the recording unit 9, which has an indicator of the integral quality assessment, by which the controller judges the suitability of the product as a whole.

If, for example, the amplifier proves unsuitable, then it is possible to carry out its diagnosis, which is carried out as follows. The signals from the outputs of the quadrators ηη of the circuits controlling one parameter are fed to the adder and an indicator for evaluating the value of this parameter. In the case when the parameter is characterized by one component frequency, the corresponding indicator is connected directly to the quadrator, the rejection parameter is determined by the readings of the indicators.

The device automates the process of monitoring all the parameters of the ULF, significantly reducing the control time, diagnoses the controlled ULF and, if the frequencies of the test signal are selected in the ratios of the consonance chord, it performs, simultaneously with objective monitoring, a subjective assessment of the sound quality of the ULF used. The device is implemented in an automatic ULF control system - Accord 114.

Claims (2)

tori, where N "1,2,3, etc. - the number of controlled parameters of the amplifier, and m 1,2,3, etc., and p 1,2,3, etc. - the number of frequency components to ci, chosen to measure each parameter, with the output of each comparing element in n circuits through a quad connected to the corresponding inputs of the pepper and (N + 1) -th adder, and the second input of the device is connected to all the inputs of N channels, the output of each quad in the m circuits x N-1 channels that are connected to the corresponding inputs of the adder in the (NI) –OM channel and to the corresponding inputs of the (N + 1) -ro adder, and the output of the quad in the circuit The channel N-ro is connected to the corresponding input of the CN-t-1) -ro adder and to the first input dy recording unit () whose input is connected to the corresponding outputs (N + 1) adders. The test signal generating unit is made up of a set of oscillators, the frequencies of which are distributed in a partial range of the amplifier being monitored, and their values correspond to the values of the tuning frequencies of the x band-pass filters. The drawing shows a block diagram of the device. The device contains a test signal forming unit 1, a control amplifier 2, n band N filters 3, gI t. Band filters N 4, rectifiers 5 and 6,, (n + STP) | quadrs 7 comparing elements 8, registering block 9, N + 1 adders 10 - liz, indicators 13 and device inputs 14 and 15. Register block 9 is a set of indicators 13 connected to adders 10 - 12. Indicators can be connected and directly to quadrants 7 for monitoring the voltage of one frequency (t is equal to 1, for example, when measuring the noise level. Indicators are made either in the form of needle instruments, light indicators, or in the form of a digital unit with data output for monitoring on a computer. The device works as follows: image Ohm. The signal from the test signal generating unit 1 is fed to the controlled amplifier 2, from the output of which the signal goes to the band-pass filters 3. After a narrow-band separation with pressure filters 3, the signal passes through the rectifiers 5. The filter components from the rectifier outputs 5 are fed to comparing elements 8, in which a comparison is made with a predetermined reference voltage. The differential voltages from the outputs of the comparing elements are sent to the lth quadrants 7, and then the first adder 11 and the (N + 1) adder 10. Od At the same time, the signal1L from the output of the controlled amplifier 2 is fed to the inputs of the filters 4, and then to the rectifier 6 and. (quadrants N i-1 7. From the outputs of Cm. quadrants 7 sign-1, filings also go to N + 1 sumN torus 10, and from 5P m quadrants 7 to the corresponding inputs (N-1) of adders 12. The sum of all distortions is given to the registering unit 9, which has an indicator of the integral quality assessment, according to which the controller judges the suitability of the product as a whole. If, for example, the amplifier turns out to be unsuitable, it is possible to diagnose it, which is carried out as follows. parameter, go to the adder and indicat An estimate of the value of this parameter. In the case when the parameter is characterized by a single component frequency, the corresponding indicator is connected directly to the quad, the indicator rejects the indications of the indicators .. The device automates the process of controlling all the ULF parameters, significantly reducing the monitoring time, and diagnoses controlled by the ULF and in the case of selecting the frequencies of the test signal in ratios of the consonance chord produces, simultaneously with the objective control, the subjective th sound quality evaluation used ULF. The device is implemented in an automatic ULF control system - Accord 114. Claim 1. Device for controlling force. low-frequency telephones containing a recording unit, a test signal generating unit connected to one of the device inputs, the second input of which is connected to the inputs of n circuits, each of which consists of a series-connected band-pass filter, rectifier and comparing element, the second input of which Connected to a voltage source, characterized in that, in order to reduce the monitoring time, quadrs, (N + 1) adders and N. channels, each of which consists of circuits connected bandpass filter, rectifier and quad, where N 1,2,3, etc., the number of controlled parameters of the low-frequency amplifier, and m 1,2, 3, etc., and p 1,2,3 and so on D. is the number of frequency components selected to measure each parameter, with the output of each comparing element in n circuits through a quad, connected to the corresponding inputs of the first and (.N. +1) -th adders, and the second input of the device is connected to all inputs of N channels, the output of each quadrant in m chains x (N -1) of channels of which are connected to the corresponding inputs of sums Ator in the (N - 1) -th channel and to the corresponding inputs of the CN + 1) -th adder, and the output of the quadr in the m circuit of the Nth channel is connected to the corresponding input of the (And + 1) -th adder and to the first input of the recording unit The (N + 1) inputs of which are connected to the corresponding outputs of the (N + 1) adders. 2. A device according to claim 1, characterized in that the test signal generating unit is implemented as a set of oscillators whose frequencies are distributed in the frequency range of the monitored amplifier, and their values correspond to the values of the tuning frequency n-th band-pass filters. Sources of information taken into account in the examination 1.Three-octave analyzer. Description. 1972, Brüel & Kjr Company, Cerum, Dani. 2. Authors certificate USSR 473127, cl. G 01 R 29/04, 1975 (prototype) ...