SU712811A1 - Apparatus for measuring the time of starting magnetic carrier - Google Patents

Description

The invention relates to the field of instrumentation, in particular to the manufacture of devices with magnetic recording media.

A device is known for measuring the start time of a magnetic medium, comprising serially connected a magnetic playback head, an amplifier driver and a trigger, the outputs of which are connected to pulse shapers of a speed deviation, two AND-NOT circuits, the first inputs of which are connected to the outputs of the formers, and the second inputs to the direct output of the trigger , OR circuit, the inputs of which are connected to the outputs of AND — NOT circuits, a reference frequency generator connected to one input of the third AND — NOT circuit, a second trigger, whose output on coupled to the second input of the third AND-circuit, and the input is connected to the bus "Start" pulse counter and the block of digital recording and display. In addition, the device includes two triggers, a counter, the elements AND — NOT and AND — OR — NOT.

The disadvantage of this device is its complexity.

The purpose of the invention is to simplify the device.

The goal is achieved by introducing a memory register connected between the counter and the registrar.

The drawing shows an electrical diagram of the device.

The magnetic playback head 1 is interfaced with a magnetic medium 2, for example, with magnetic tape, the driver amplifier 3 is connected to a counting trigger 4. The direct output of the trigger 4 is connected to AND-NOT 5, 6 circuits and through pulse shapers 7, 8 and circuits 5, 6 connected to the 10th input of the OR circuit 9. Tires 10 of the “Start” command through trigger 11 are connected to one input of the And 12 circuit, the reference generator 13 is connected to the second input of it. registration and indication. To the input of the register register 15 is connected the output of circuit 9.

The device operates as follows.

The “Start” command starts the magnetic carrier 2 from the start bus 10, on which a signal with a fixed period is preliminarily recorded, and trigger 11 is set25 to a single state. The trigger signal And opens the circuit And 12, through which from the reference generator 13 to the counter 14 of the number of pulses, pulses with a period T _about begin to arrive.

The signal from the magnetic medium 2 is read using the magnetic head 1

4 of playback and through the amplifier-driver 3 is supplied to the counting input of trigger 4. The signal from the direct output of trigger 4 with a negative edge starts the driver 7 of positive pulses of the shortest duration, and the signal from the inverse output - driver 8 of negative pulse pulses of the longest duration corresponding to the largest _ma kc and smallest deviation Umni instantaneous speed of movement of the magnetic carrier of the rated speed value.

If the speed of movement of the magnetic medium 2 is less than the specified lowest speed and _min , then the signal reproduction period t _L - (positive signal level at the direct output of trigger 4) is longer in duration of the negative signal of the former 8 of the longest specified duration. At the end of the signal of the shaper 8 at the output of the AND — NOT 6 circuit, a negative signal appears, which, through the OR circuit 9, generates a command to write to the register 15 counter value 14.

If the speed of movement of the magnetic medium 2 is greater than the specified maximum Omake speed, then the period of the reproduced signal τ _χ (negative signal level at the direct output of trigger 4) is shorter than the duration of the positive signal of the shaper 7 of the shortest specified duration. At the end of the signal of the shaper 7, a negative signal appears at the output of the AND — NOT 5 circuit, which writes the value of counter 14 to the register 10 through the OR 9 circuit. This process occurs every time the instantaneous speed of the carrier exceeds a predetermined speed corridor up or down.

When the starting transition process ends and the speed of the magnetic medium is established, the signals do not appear at the outputs of circuits 6, 5. Thus, the value of the number of pulses Ν corresponding to the start time Δί = Λ '· 7 _{0 of the} magnetic carrier 2 is recorded in the register 5. The measurement result from register 15 is recorded in the digital block 16 for registration and indication.

When using the invention, the number of elements is reduced in comparison with the known, which helps to reduce the cost and increase the reliability of the device 15.

Claims (1)

Claim A device for measuring the start time 20 of a magnetic medium containing a magnetic playback head connected in series, an amplifier-driver and a trigger, to the outputs of which are connected speed drivers of deviations of speed 25, two AND-NOT circuits, the first inputs of which are connected to the outputs of the formers, and the second inputs to direct trigger output, OR circuit, the inputs of which are connected to the outputs of AND-NOT circuits, a reference frequency generator 30 connected to one input of the third AND-NOT circuit, the second trigger, the output of which is single with the second input of the third AND — NOT circuit, and the input is connected to the Start bus, a counter of 35 pulses and a digital registration and indication unit, characterized in that, in order to simplify the device, it is equipped with a memory register connected between the output of the counter and the unit digital registration and indication, and the input of the register record is connected to the output of the OR circuit. NGO "Search" Order 2798/19 Ed. Number 138 Circulation 497 Subscription Printing house, 2 Sapunova ave.