SU1216796A1 - Device for checking parameters of magnetic heads - Google Patents

Abstract

The invention relates to the field of instrumentation and can be used to control the parameters of magnetic heads in large-scale production and input control of consumer enterprises. The device contains a current generator 1 podmagnichamp, controlled dividers 2 and 3, output terminals 4, keys 5 and 12 audio frequency, generator 7 g of recording high-frequency signals. and: a measuring resistor 8, a low frequency filter 9, a ppdm gnification frequency filter 10, an analog-to-digital converter 13, a biasing frequency switch 14, a high frequency recording level driver 15, a magnetic control head 16, a third frequency harmonic filter 17 , comparison circuits 18-20, a third harmonic amplitude sensor 21, a recording level setting unit 22, a high frequency signal dropping level setting 23, AND 24, 25 elements, a counter 26. Interconnecting these elements in a certain way allows you to increase exactly be parameters of magnetic agile. 1 il. i (L S W o o: o h

Description

The invention relates to instrumentation and can be used to control the parameters of magnetic heads in large-scale production and input control of consumer enterprises.

The purpose of the invention is to improve the accuracy of the welding parameters of magnetic heads.

Pa drawing shows a block diagram of a device for checking the parameters of magnetic heads.

The device contains a bias current generator 1, the first 2 and second 3 controlled dividers, output terminals 4j nepBbBi key 5 audio frequency, current generator 6 low frequency signal recording, current generator 7, high frequency signal recording, measuring resistor 8, filter 9 low frequency filter 10 frequency bias, fourth comparison circuit 11, second key 12 audio frequency, analog-to-digital converter 13 key 14 bias frequency, high frequency recorder 15 high frequency recording, control. magnetic roj OBKy 16, 17 tr filter tey low chastoty- harmonic signals, the first 18, second 19 and third comparator circuit 20, dial 21, the amplitude of the third harmonic, the dial 22 prior zapisid layer for signal decay Occupancy 23 Bk high frequency of the first 24 and second 25 elements AND counter. 26 duration of mixing tape.

The device for checking the parameters of the magnet1 heads works in the following direction.

The bias current generator 1 generates a biasing current and, via the first divider 2, supplies it to the input of the head via output terminals 4. At the same time, from the low frequency recording current generator 6, through the first audio key 5 and through the second control divider 3 low frequency recording current receives the same input of the test head, the bias current is set by the first controlled divider 2 higher than the nominal, and the low frequency recording current is controlled by the second minimum divider controlled. With the advancement of the magnetic tape on the magnetic heads, a current is recorded

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recording the low frequency of the test head and its reproduction with the control head 16. The reproduction level of the low frequency signal is compared in the first comparison circuit 18 with the nominal recording level set by the recording level generator 22. At the same time, the third harmonic filter 17 of the low-frequency signals comprises the level of the third harmonic from the reproduced low-frequency signal, which is compared with the preset value set by the unit 21 of the third harmonic. At each interval of time equal to the movement time of the tape section from the test head to the control head 16, the counter for the movement of the tape 26 produces clock pulses, which are fed to the second controlled divider 3 ,, increasing the recording current for each clock 1-pulse.

When the reproduced signal reaches the levels set by setters 21 and 22, signals from the comparison circuits 20 and 18 arrive at the second And 23 element. According to these signals, the second element I 25 generates a signal 5 which prevents the generation of clock pulses by the counter 26 of the duration of the movement of the tape. A cn-nal from the second element I 25 closes the second key 12 of the audio frequency and the low-frequency recording current, extracted from the signal of the 9-frequency signal from the signal present on the measuring resistor 8, is fed to the input of the analog-digital converter 13, which measures em amplitude. The digital code from the output of the analog-to-digital converter 13 is fed to an external bus for processing and tacles to the data input of the high-frequency recording level generator 15 and is memorized by a signal from the second element AND 25, by a signal from the second element 25 by the audio frequency, which connects the high frequency recording current reiieparopa 7 output through the second controllable divider 3 to the test head input. At this time, CiiHxHHo clock signals with signals

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generator 7 current recording high frequency. The controlled divider 3 increases the high frequency current that is extracted by the low frequency filter 9 and is compared by the fourth fourth comparison circuit 11 with the level set by the M shaper 15 of the write level. When equality occurs, the fourth circuit compares the signal 11, which prohibits the generation of clock pulses that are synchronous with a high frequency.

The recorded high frequency is reproduced by the reference magnetic head. The reproduced signal is compared in the first 18 and third 19 comparison circuits, respectively, with the levels set by the setter.

22 level recording and setting point

23 levels of high frequency decay. Counter 26 duration

belt movements are generated by clock pulses with a period equal to the time that the belt moves from the test head 4 to the control head 16, which are fed to the first control divider. Managed deli. tel each measure reduces

bias current. The bias current decreases until the playback level drops from the recording level.

set by the level 22 adjuster

Records up to the level set by the knob 23 of the high-frequency signal decay level. When the playback level declines, the element And 24

produces a signal by which z.ap

the generation of clock pulses by the counter 26 of the duration of the movement of the tape section, which is initiated on the first controlled divider 2, is decided. This signal also closes the key 14 of the bias frequency, through which the bias current supplied by this filter 10, which connects the bias frequency 14, and connects

its input to the analog-to-digital converter 13, which measures and the digital code is transmitted to the external bus.

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Claims (1)

Invention Formula Device for checking the parameters of magnetic HEADS containing bias current generator, co0 five 0 five 6 five 0 five 0 five 0 five 796. One controlled output divider with the output of the second controlled splitter and one of the output terminals, low and high frequency recording current generators, a recording level setter, the output of which is connected to the first input of the first circuit (comparison, the second input of which is connected to the control magnetic head and the input of the filter of the third harmonic of the low frequency signal, the setting unit of the amplitude of the third harmonic, the output of which is connected to the first - the input of the second comparison circuit, the second input of which is connected to the output of the third harmonic filter a low frequency signal, a low frequency filter, that is, so that, in order to increase the accuracy of the test, it introduced a descriptor of the signal decay level, high frequency, third and fourth comparison circuit, The first and second elements are And, the tape travel duration counter, the high-frequency recording level former, the analog-to-diffraction converter, the magnetization frequency filter, the first and second keys of the audio signal, the bias signal key, and the measuring resistor, and the output of the level gauge A high frequency drop is connected to the first input of the third comparison circuit, its second input is connected to the control magnetic head, and the output is connected to the first input of the first And element, the second input of this element is connected to the first input of the second And element, and to the output of the first comparison circuit, the output of the first element I is connected to the first control input of the counter of the duration of the movement of the magnetic tape and with the control input of the key of the biasing signal, the second input of the second element I is connected to the output of the second comparison circuit, and its the output is with the second control input of the tape travel duration counter and with the control inputs of the first and second KEY of the audio frequency signal, as well as a high-frequency recording level generator, whose information input is connected to the output of the analog-digital converter and the second input of the fourth circuit compare, the first entry of this of the circuit is connected to the output of the low-pass filter and to the input of the second key of the audio signal, the output of the fourth comparison circuit is connected to the third control input of the tape moving time counter, the information input of which is connected to the output of the high frequency signal recording current generator and to the second the input of the first key of the audio signal; the outputs of the counter are connected respectively to the control inputs of the first and second controlled dividers, the first input of the nepadro signal key Compiler A.Eroshkevich Editor O.Golovach Tehred O.Neda Proofreader E.Sirohman Order 1002/59 Circulation 544 Subscription VNISHS USSR State Committee for inventions and discoveries ° 113035, Moscow, Zh-35, Raushsk nab, d. 4/5 Branch PGS Patent, Uzhgorod, st. Project, 4 the audio frequency is connected to the output of the current generator of the low frequency signal, and the output of the key is connected to the input of the second controlled divider, the input filter of the bias frequency is connected to the second output terminal, to one of the terminals of the measuring resistor and to the input of the low frequency filter, another terminal of the measuring resistor connected to the common wire of the device, the output of the filter bias frequency is connected via a key of the bias frequency signal to the output of the second key of the audio signal and to the input of the analog-differential signal verters.