SU576606A1 - Magnetic tape speed measuring device - Google Patents

Description

one

The invention relates to the field of instrumentation and to be used in a magnetic recording apparatus.

A device for measuring the velocity of a moving mite containing a magnetic head with two working gaps, connected to amplifiers, drivers, recording unit, detectors, demodulator, and a constant constant pulse of 1J is known. This device is not sufficiently deactivated.

A TaKJKe device is known in which pmpulses of the reference frequency are used to increase speed. A counter, a register, a decoder, and a series of logic circuits constitute the channels for passing the measured voltage 2J. However, this device is designed for relatively large changes over time, as a result of which the final speed is reduced.

The closest to the invention in its technical essence is a device for measuring the speed of movement of a magnetic tape, containing 1 its magnetic heads connected to amplifier-formers, one of which is associated with the first coincidence circuit, and the second with a first trigger, connected to the output of this coincidence circuit is a serially connected second trigger, a second soviadenp circuit, a counter, a register and a frequency divider, a reference frequency generator associated with the second input of the second coincidence circuit, and the first and second blocks jacks whose outputs are interconnected, and

flea control 3J.

This device has insufficient speed and accuracy of measurements.

To improve the accuracy and speed of measurements, the proposed device is equipped with an AND-OR-NOT circuit whose output is connected to the first delay unit and to the register, an inverter connected to the first input, and a controlled delay unit connected to the second input of this

AND-OR-IE circuits, between which the control unit is connected, the third input of the circuit is connected to the input of the inverter and the output of the control unit, and the fourth to one of the driver amplifiers, both

the triggers and the input of the controlled delay unit, the input of the second delay unit is connected to the counter and the first trigger.

The drawing drawing is a structural diagram of the updated device.

The signal reproduced from the magnetic tape I by the head 2 through the amplifier-shaper 3 and the first coincidence circuit 4 falls on the trigger 5. From this trgger and from the generator 6 of the reference frequency through the second circuit

7 matches, counter 8, trigger 9 sigal

comes to the frequency divider 10. Magnetic head 11 through the driver-shaper 12 is connected simultaneously to the trigger 13 and to the AND-OR-HE 14 circuit connected with the first delay block 15. The second delay block

16c is engaged with trigger 13, and the control unit

17 together with the inverter 18 and the controllable delay unit 19 — with the circuit 14.

When the signal is reproduced by the head 2, the trigger 5 goes into one state, and the signal from the trigger output opens the circuit 7. The pulses from the generator 6 arrive at the counter and then on the register. The same signal, reproduced by the head 11, sets to one and the trigger 13, the delay block 19 is started and the register value is reset through the circuit 14. Then the signal from the output of the flip-flop 13 closes the circuit 4 and eliminates the possibility of triggering the flip-flop 5 during the processing process and recording the measurement results. The signal from the circuit 14 through the delay block 15 now enters the register, thus making it possible to realize the necessary co.mapdue. The signal delayed in block 16 resets the counter and re-establishes trigger 13 as a single state, thereby allowing a new measurement cycle.

Claims (3)

1. Certificate of author No. 355656, cl. G IW 15/46, 1970. 2.Natent USA 3829893, cl. 360-73, publ. 1974. 3. United States f 3320600, cl. 340-174.1, publ. 1967.