RU1780110C - Control device of start-stop drive on magnetic tape - Google Patents

Abstract

Usage: the invention relates to drive control devices for a start-stop tape drive. SUMMARY OF THE INVENTION: generating a braking signal depending on the ratio of the diameters of the rolls of tape from signals from photosensors in two electric motors. For this purpose, a counter of the driving electric motor is used, the filling of which is two times less than that of the counter of the supplying electric motor. When the ratio of roll diameters reaches 2: 1, the counters are filled at the same time, which makes it possible to generate a "brake" signal in the command block. 1 ill.

Description

The invention relates to a technique for storing information, in particular, to controlling a magnetic tape drive without a drive shaft for start-stop drives with zone recording of information, and is an improvement on the known technical solution of St. Petersburg 1707066.

The known drive control device comprises two side motor motors with control units and two rotation speed sensors made in the form of a series-connected photosensor and a frequency-voltage converter, a comparison unit, a pulse-width modulator and a frequency distribution unit, a braking unit, and two the integrator of the lead and feed motors are connected by outputs to the inputs of the second switch, two inputs of the first switch are connected to the inputs of the adder and vyhodamipreobrazovateley

frequency-voltage, and its two outputs, respectively, with the inputs of the comparison unit and the input of the feed motor integrator, the output of which is connected to the input of the second switch, the output of the adder is connected through the comparison node to the input of the integrator of the driving motor, the four inputs of the frequency distribution unit are connected to the outputs respectively, the braking unit, two photosensors and a pulse-width modulator, and its three outputs - with two inputs of the control unit and the input of the braking unit, the first output of the command block with is dined with the input of the first switch and the input of the frequency distribution unit, the second output with the corresponding inputs of the frequency-voltage converters, the third output with the input of the comparison unit and the input of the braking unit, the fourth output with the input of the first switch, the input of the frequency distribution unit and the input of the second switch, fifth

the output is with the input of the braking unit and the input of a pulse-width modulator, and its sixth output is with the input of the braking unit.

The disadvantage of this device is the possibility of tearing off or leaving the coils of the magnetic tape in the event of a marker stop failure, i.e. the lack of a brake signal from the command block. Failures during operation of the start-stop drive also occur, for example, when operating in severe climatic conditions, which affects the quality of markers consisting of translucent sections at the ends of the magnetic tape, since the tape is torn off or disembarking it from coils is a loss of operability, then, therefore, the drive control device also has low reliability for this reason.

The aim of the invention is to increase reliability in severe climatic conditions by eliminating tearing or slipping of the magnetic tape from the coils in the event of a marker stop.

This goal is achieved by the fact that the third switch is introduced into the device 8, as well as two chains, the first of which is made in the form of series-connected first meters, the first one-shot and RC circuits, and the second - in the form of series-connected second meters, matching circuits and the second one-shot, the output of the first counter connected to the second input of the matching circuit, the output of the RS-circuit with the input reset of the first / second counter, the output of the second one-shot with the input of the command block, the first output of which is connected to the control conductive input of the third switch, whose two inputs - with the output of each photosensor.

The drawing shows a structural diagram of the device.

The device comprises two electric motors 1, a control unit 2, which includes two channels for each of the electric motors in the form of a decoder 3 connected in series and a power amplifier 4, to which a six-digit switching code of the winding of the corresponding electric motor is supplied, two speed sensors 5, consisting of a series-connected photosensor 6 and a frequency-voltage converter 7, an adder 8, two switches 9 and 10, two integrators 11 and; 12, a control unit 13 generating and amplifying an error signal, a pulse-width modulator 14, to one of the inputs of which a reference frequency FonopH of 42 kHz is supplied from the output of the command unit 15.

which generates control signals backward movement, acceleration, start-up, braking, ML (magnetic tape) tension, comparison unit 16, braking unit 17, frequency distribution unit 18, third switch 19, as well as two chains, the first of which are made in VI , a, e connected in series to the first counter 20, the first one-shot 23 and the RC circuit 25,

and the second, in the form of series-connected second counter 21, matching circuit 22 and second single vibrator 24, the output of the first counter 20 being connected to the second input of matching circuit 22,

the stroke of the RC circuit 25 - with the input reset the first 20 and second 21 counters, the output of the second one-shot 24 with the input of the block 15 teams, the first output of which is connected to the control input of the third switch 19, and

two of its inputs - with the output of each photosensor 6, two outputs of the first switch 9 are connected to the inputs of the adder 8 and the outputs of the frequency-voltage converters 7, and its two outputs, respectively, with

the inputs of the control unit 13 and the inputs of the integrator 11 of the feed motor, the output of which is connected to the input of the second switch 10, the output of the adder 6 is connected via a node 16 compared to the input of the integrator 12 of the drive motor, the four inputs of the frequency distribution unit 18 are connected to the outputs of the corresponding braking unit 17 photodag-: -1kos 5 and pulse-width modulator 14, and three

its output - with two inputs of block 2 of the simplification and the input of the node 17 by

input of the first switch

entrance

frequency distribution unit 18, the second input is with the corresponding input, frequency converter 7, the third output is with the input of the comparison unit 16, the frequency distribution unit 18 and the input of the H / braking unit, the fourth output is with the input of the first switch 9 , input. frequency distribution unit 18 and the input of the second switch 10, the fifth output is with the input of the braking unit 17 and the output of the u-pulse-modulator 14. and its sixth output is with the input of the braking unit 1 7.

The device operates as follows --- manner.

The braking mode is implemented using a signal from a command block. To the block 13 with the direct i-i and L: through the switch 9, the integrator 11 of the feed motor is connected, simultaneously through the switch 10 from this blog; a converted slave speed signal is supplied. A linearly decreasing voltage (braking characteristic) is supplied from the integrator 11 of the feed motor. From the output of the comparison unit 13, the braking is linearly applied via the pulse width modulator 14, the frequency distribution unit 18 and the power amplifier unit 4.

To prevent an emergency ML exit (reeling) in the event of a failure of the marker stop device, short pulses from the photosensors of the driving and feed motors are received at the counters 20 and 21. Their counting is always organized using the switch 19 so that at the output of the counter 20 of the driving electric motor a signal is triggered after 128 pulses, triggering the single-shot 24. At the end of the time interval formed by it, a short pulse is generated by the RC chain 25, which resets the counters 20 and 21 .

When the frequency of the signals from the sensors 5 of the rotation speed of the driving and feeding motors is 2: 1, which corresponds to the end of the ML roll, both counters 20 and 21 count their sum at the same time. Since the reset from the first counter 20 is delayed for the duration of the pulse from the one-shot 24, the second counter 21 forms, using the matching circuit 22, the start of the one-shot 23, the signal from which goes to the input of the command block 15 instead of the signal from the stop marker (not shown). Thus generating a signal

braking in the device is duplicated by the proposed circuit.

Claims (1)

SUMMARY OF THE INVENTION Drive control device for a magnetic start / stop drive Autotransfer tape Ме 1705866, characterized in that, in order to increase the reliability of operation in severe climatic conditions by eliminating the breakage or bypassing of the magnetic tape reels in the event of a marker stop, a third switch has been inserted into it, as well as two chains, the first of which is made in the form of series-connected first counter, the first one-shot and RC-circuit, and the second - in the form connected in series to the second counter, the match circuit and the second one-shot, the output of the first counter connected to the second input of the match circuit, the output of the RC circuit to the reset input of the first and second counters, the output of the second one-shot to the input of the command block, the first output of which is connected to the control the input of the third switch, the two inputs of which are with the output of each photosensor.