SU533977A1

SU533977A1 - Device for automatically controlling the speed of movement of a magnetic tape

Info

Publication number: SU533977A1
Application number: SU2139185A
Authority: SU
Inventors: Виктор Семенович Юрасов; Александр Маркович Верба
Original assignee: Предприятие П/Я А-7358
Priority date: 1975-05-20
Filing date: 1975-05-20
Publication date: 1976-10-30

Description

1one

Изобретение относитс к области приборостроени , а именно к аппаратуре магнитной записи и воспроизведени .The invention relates to the field of instrumentation, in particular to magnetic recording and reproducing apparatus.

Известны устройства дл автоматического регулировани скорости перемещени магнитной ленты 1-4. Во всех этих устройствах сравнение опорного сигнала и сигнала датчика скорости осуществл етс фазовым дискриминатором .Devices are known for automatically controlling the speed of movement of the magnetic tape 1-4. In all these devices, the comparison of the reference signal and the speed sensor signal is made by the phase discriminator.

Наиболее близким по технической сущности к предлагаемому вл етс устройство дл автоматического регулировани скорости перемещени магнитного носител , содержащее задающий генератор, соединенные с ним фазовый дискриминатор, первый частотный дискриминатор и усилитель записи с последовательно подключенной магнитной головкой записи , включенные на выход коммутатора, делитель частоты, соединенный с вторым входом фазового дискриминатора, и второй частотный дискриминатор. Выходы обоих частотных и фазового дискриминаторов подключены к соответствующим входам сумматора, выход которого через усилитель-преобразователь соединен с двигателем, сопр женным с магнитной лентой и валом тахогенератора, причем последнего соединен с первым управл ющим входом коммутатора, на второй вход которого подаетс сигнал с магнитной головки воспроизведени через усилитель воспроизведени 5.The closest in technical essence to the present invention is a device for automatically controlling the speed of movement of a magnetic carrier, comprising a master oscillator, a phase discriminator connected to it, a first frequency discriminator and a recording amplifier with a serially connected magnetic recording head connected to the switch output, a frequency divider connected with the second input of the phase discriminator, and the second frequency discriminator. The outputs of both frequency and phase discriminators are connected to the corresponding inputs of an adder, the output of which is connected via an amplifier-converter to a motor connected to a magnetic tape and a tachogenerator shaft, the latter being connected to the first control input of the switch, to the second input of which a signal is fed from the magnetic head playback through the playback amplifier 5.

Недостатком известного устройства вл етс то, что в режиме воспроизведени приA disadvantage of the known device is that in the playback mode when

кратковременных пропадани х контрольного сигнала, записанного с выхода задающего генератора , или при его исчезновении, например , вследствие дефектов магнитной ленты, плохого контакта лента-головка, происходитshort-term loss of the control signal recorded from the output of the master oscillator, or when it disappears, for example, due to magnetic tape defects, poor tape-head contact, occurs

нарущение работы устройства регулировани . Цель изобретени - повыиление надежности работы устройства дл регулировани скорости перемещени магнитной ленты. Это достигаетс тем, что в предлагаемоеmalfunction of the control device. The purpose of the invention is to increase the reliability of the device for controlling the speed of movement of a magnetic tape. This is achieved by the fact that

устройство введены последовательно соединенные амплитудный детектор и компаратор, включенные между выходом усилител воспроизведени и силовым входом коммутатора. На чертеже показана функциональна схема устройства дл автоматического регулировани скорости неремещеии магнитной ленты .A device is connected in series with an amplitude detector and a comparator connected between the output of the playback amplifier and the power input of the switch. The drawing shows a functional diagram of an apparatus for automatically controlling the speed of non-displacement of a magnetic tape.

Устройство содержит задающий генератор 1, первый частотный дискриминатор 2, фазоBbiii дискриминатор 3, усилитель-преобразователь 4, двигатель 5, тахогеиератор 6 второй частотный дискриминатор 7. делитель частоты 8, сумматор 9, усилитель записи 10, магнитные головки записи и воспроизведени 11,The device contains a master oscillator 1, the first frequency discriminator 2, phase Bbiii discriminator 3, amplifier-converter 4, engine 5, tachoheizer 6 second frequency discriminator 7. frequency divider 8, adder 9, recording amplifier 10, magnetic recording and playback heads 11,

Claims

12, a playback amplifier 13, a switch 14 having two control inputs and one power, as well as an output, an amplitude detector 15, a comparator 16, and a magnetic tape 17. The device operates as follows. 5 In the steady state recording mode, the motor 5 rotates at nominal speed. The feedback signal, whose frequency is proportional to the speed of rotation of the tachogenerator 6, through the control input of the switch 14 is fed to the input of the frequency discriminator 7, and also through the frequency divider 8 to the second input of the phase discriminator 3. At the same time, the signal from the generator output 1 is fed to the first input of the phase discriminator 15 and 3 and to the inputs of the frequency discriminator 2 and the recording amplifier 10, the output of which is connected to the recording head 11, and the control signal produced by the generator I.2 is recorded on the magnetic tape 17 0 The output of the phase discriminator 3 generates an error signal proportional to the phase angle between the control signal and the feedback signal. The voltage from the outputs of the phase and frequency dis-25 criminators 3, 2, 7 is fed to the corresponding inputs of the adder 9. From the output of the adder 9, the signal is fed to the input of the amplifier-converter 4, which is amplified and converted into a control signal that is supplied to the motor 5, maintaining its rotational speed to the synchronous frequency of the master oscillator 1. The second frequency discriminator 7 generates a voltage proportional to the deviation35 of the frequency of the master oscillator 1, i.e., regulates the device operation in transient conditions and The frequency of the master oscillator 1. The first frequency discriminator 2 improves the control accuracy, increases the synchronization range of the device, and allows you to smoothly change the speed of the magnetic tape movement by changing the frequency of the master oscillator 1. In the Power Amplifier 45 13 mode, the control signal is fed to the input an amplitude detector 15, where the average value of the voltage of said signal is extracted, which is fed to the input of the comparator 16 and is compared with the bias voltage 50 produced by it . If the voltage of the amplitude detector exceeds the bias voltage, then the output of the comparator 16 generates a command to the power input of the switch 14. By this command, the control-55 signal from the output of the amplifier 13 is passed through the switch 14 to the inputs of the frequency discriminator 7 and frequency divider 8 The device works in this case in the mode of stabilizing the time scale, i.e., the PCO control signal from the magnetic tape 17. In case of a loss of the control signal, the voltage at the output of the amplitude detector 15 becomes less zhenp bias voltage, and a power input switch is removed May 14 wherein said command above. In this case, the inputs of frequency divider 8 and frequency discriminator 7 are connected via switch 14 to the output of tachogenerator 6, from which the feedback signal is received. The switch 14 can be performed both on the electromagnetic relay and on the contactless circuit. Thus, in the Playback mode, the control signal (if available at the output of the playback amplifier 13) or the signal from the tachogenerator 6 (in the absence of the control signal) is used as a feedback signal. The introduction of an amplitude detector and comparator into a device for automatically controlling the speed of movement of the carrier significantly increases the reliability of its operation, and hence the reliability of the magnetic recording apparatus, significantly reduces the probability of information loss due to carrier defects, tape-to-head contact, etc. the solution allows the creation of a better and more reliable magnetic recording and reproducing apparatus, the claims of the device for automatic regulated the traveling speed of the magnetic tape, comprising: a master oscillator, connected to it a phase discriminator, a first frequency discriminator and an amplifier connected in series with a recording magnetic recording head, included in the output switch, a frequency divider, coupled to the second input of the phase discriminator and a second frequency discriminator; the outputs of both frequency and phase discriminators are connected to the corresponding inputs of the adder, the output of which is connected via an amplifier-converter to a motor connected to a magnetic tape and a tachogenerator shaft, the output of which is connected to the first control input of the switch, to the second of which a signal is fed from the magnetic head playback through a playback amplifier, characterized in that, in order to improve the reliability of the device, sequentially connected amplitude detectors are introduced into it Op and a comparator connected between the amplifier output and the reproducing power input switch, information sources, the received note in the examination: 1.Patent № US 3549797, cl. 178-6.6, 12.22.70.

2. US Patent Hell Security, cl. 242-186, 09/20/71.

3. US Patent L 366883, cl. 178-6.6, 30.05.72. five

4. Japan patent number 12078, cl. 04.14.72. 102E215.2,

5. Auth. St. No. 446023, Q 05B 11/00 08 7 533977 6 (prototype).