SU605264A1 - Device for measuring magnetic carrier starting time - Google Patents

Description

one

The invention relates to instrumentation, in particular to a device for measuring the start-up time of magnetic media used in a magnetic recording apparatus (AMR).

A device for measuring the start-up time of a magnetic carrier (MI), made on the basis of a frequency discriminator, comparison and coincidence circuits, in which the received pulses are differentiated, is known. With such a device, it is possible to obtain sufficiently accurate results.

The need to translate the obtained values into those units, which in each individual case are used to obtain true results, reduces the accuracy of the readings and complicates the maintenance of such a device.

Closest to the invention is a device for measuring the start-up time of a magnetic carrier, containing the “Start and serially connected magnetic reproduction head commands, amplifier driver and first trigger, one output of which is connected to the first input through serially connected devices” the OR circuit, and the other output through the serially connected second driver and the AND – IE circuit is connected to the second input of the OR circuit 2.

This device does not have a sufficiently high speed. If you try to increase the speed, the accuracy of its operation and output is reduced.

The aim of the invention is to improve the accuracy and speed of obtaining measurement results.

For this, the device is supplied with two consecutive electrical circuits

the first of which contains the second trigger, the AND-OR-PE scheme, the first counter and the recorder, and the second the third trigger, the third AND-IE scheme and the second counter associated with the output of the OR scheme and with the second input

third trigger; an inverter connected between the first driver and the I-IE circuit; a reference frequency generator connected to the inputs of the third AND-IE circuit and the AND-OR-IE circuit, a separate input of which is connected to the output of the third IS-NOT circuit, while the second inputs of the second and third triggers are connected to the Start command, and the output of the first trigger - with the second inputs of the first and second circuits AND-IE.

The drawing shows the block diagram of the described device.

The magnetic head 1 reproduces the signals from the magnetic carrier 2, which through the amplifier-shaper 3 arrive at the output of the first trigger 4. From the same trigger

the signals are sent to the first AND-NOT circuit 5 and to the second AND-NOT circuit 6, as well as through the first driver 7 - to the inverter 8 and directly to the second driver 9. The driver 7 produces pulses of minimum duration, and driver 9 - pulses of maximum duration. Both AND-NOT schemes are loaded onto the OR-10 scheme. The device also uses the second

11and third 12 triggers. The first one through the AND-OR-NOT 13 scheme and the first counter 14 is connected to the recorder 15, and the second, together with the reference frequency generator 16, is connected to the third AND-NE 17 scheme loaded on the second counter 18. Triggers 11 and 12 are connected to bus 19 teams "Start.

When applying the command “Start Triggers 11 and

12 is set to one state, which opens circuits 13 and 17, through which pulses from the generator begin to flow into both counters. The signals from carrier 2 through the head and the amplifier arrive at trigger 4 and then alternately start drivers 7 and 9. When a pulse arrives at circuit 5, the duration of which is less than the preselected minimum duration, a positive pulse appears at the output of circuit 5 resets the counter 18. If the duration of the period of the reproduced signal, having the form of a positive pulse, at the output of the trigger 4, is longer than the maximum received duration of the negative pulse by you If the driver 9, then the output of the circuit 6 is a positive pulse, which through the OR circuit also resets the counter 18 to the initial state, i.e., the output of the OR circuit appears every time the period of the reproduced signal greater than the longest and shorter of the shortest duration specified by the operating conditions of both drivers 7 and 9.

As a result, the counter 18 is reset to its original state each time when the instantaneous speed of the magnetic carrier does not correspond to the specified values. This allows you to instantly obtain the required measurement results and, moreover, with high accuracy, which is very important for assessing the quality of AMZ.

F o rm) l and inventions

A device for measuring the start-up time of a magnetic medium, comprising a start command bus and serially connected magnetic reproducing head, a driver amplifier and the first trigger, one

the output of which through serially connects the valuable first driver and the circuit AND IS NOT connected to the first input of the OR circuit, and the other output through the serially connected second driver and circuit

I-NOT is connected to the second input of the OR circuit, characterized in that, in order to increase the accuracy and speed of obtaining measurement results, it is equipped with two consecutive electrical circuits, the first of which contains a second trigger, an AND-OR circuit, a first counter and the recorder, and the second is the third trigger, the third NAND circuit, and the second counter associated with the OR circuit output and the second

the entrance of the third trigger; an inverter connected between the first driver and the NAND circuit; a reference frequency generator connected to the inputs of the third AND-NOT circuit and the AND-OR-NOT circuit, a separate input of which is connected to the output of the third AND-NOT circuit, while the second inputs of the second and third triggers are connected to the Start command bus, and the output of the first trigger - with the second inputs of the first and second AND-NOT circuits.

Information sources,

taken into account in the examination

1. USSR author's certificate number 455021, cl. G 04F 9/06, 1973.

2. USSR author's certificate number 429403, CL. G 04F 9/06, 1973.