SU803004A1 - Device for indicating the quantity of magnetic tape - Google Patents

Description

The invention relates to the field of information storage, and in particular to devices for indicating the amount of magnetic tape. j

A device for indicating the number of magnetic tape containing a sensing element, mounted with the ability to | directly interface with the magnetic tape and connected to the registration unit [1], is known. The known device provides a relatively high accuracy of the indication of the number of magnetic tape.

The disadvantage of such a device is the complexity of its design.

It is also known a device for indicating the amount of magnetic tape containing a transceiver element installed along the radius of the roll of magnetic tape against its turns, an amplifier, the output of which is connected to the recording unit and an AC voltage source [2]. This device has a relatively simple design.

The disadvantage of this device is its large dimensions. 3Q

The purpose of the invention is to reduce the size of the device for indicating the number of magnetic tape.

This is achieved due to the fact that a switch is inserted into the proposed device, connected between the output of the AC voltage source and the amplifier input and connected to a transceiver element made in the form of a rod-shaped piezoceramic transducer of acoustic vibrations mounted with the possibility of perceiving air vibrations excited by it after reflection from the roll magnetic tape and changes in its electromotive force when changing the number of turns of a roll of magnetic tape.

The drawing shows one of the possible variants of the proposed device for indicating the number of magnetic tape.

The proposed device contains a transceiver element 1 mounted on the base 2 along the radius of the roll 3 of the magnetic tape against ’its turns. The transceiver element 1 is connected to the switch 4 and is made in the form of a rod-shaped piezoelectric ceramic transducer of acoustic vibrations mounted with the possibility of perception of the air vibrations excited by it after their reflection from the roll 3 of the magnetic tape. In this case, the rod-shaped piezoceramic transducer of acoustic vibrations has the ability to change its electromotive force when changing the number of turns of a roll 3 of magnetic tape. , _

In the proposed device, a switch 4 is connected between the output of the AC voltage source, for example, the source of the ultrasonic signal, and the input of the amplifier 6. The output of the amplifier is connected to the recording unit 7. fifteen

In the proposed device, a rod-shaped piezoceramic transducer of acoustic vibrations excites ultrasonic air vibrations acting on a roll 3 of magnetic tape. After reflection from the roll 3 of the magnetic tape, these air vibrations act on a rod-shaped piezoceramic transducer of acoustic vibrations. The latter leads to the fact that the rod-shaped piezoceramic transducer of acoustic vibrations generates an electromotive force, the change of which is proportional to the change __ of the number of turns of roll 3 of the magnetic tape.

Therefore, the proposed device for indicating the amount of magnetic tape has significantly reduced dimensions, more simply in design and operation.

Claims (2)

(54) A DEVICE FOR INDICATION OF THE QUANTITY 1 OF AN AGRICULTURAL TAPE of a ceramic transducer of acoustic oscillations mounted to perceive the excited vibrations of air after they are reflected from the roll 3 of magnetic tape. In this case, a rod-shaped piezoceramic transducer of acoustic oscillations has the ability to change its electromotive force with a change in the number of turns of the roll 3 of the magnetic tape. In the proposed device, switch 4 is connected between the output of a source of alternating voltage 5, such as an ultrasonic signal source, and an input of amplifier 6. The output of amplifier 6 is connected to recording unit 7. In the proposed device, a rod-shaped piezoceramic transducer of acoustic oscillations excites ultrasonic vibrations of air acting on a roll 3 of magnetic tape. After reflection from the roll 3 of the magnetic tape, these air vibrations act on the rod-shaped, piezoceramic transducer of acoustic vibrations. The latter leads to the fact that a rod-shaped piezoceramic transducer of acoustic oscillations generates an electromotive force, the change of which is proportional to the change in the number of turns of rolls 3 of the magnetic tape. Therefore, the proposed device for indicating the amount of magnetic tape is significantly reduced in size, simpler in design and in operation. Claims An apparatus for indicating the quantity of a magnetic tape, comprising a transceiver element mounted along the radius of a roll of magnetic tape against its turns, an amplifier whose output is connected to a recording unit, and a source of alternating voltage, in order to reduce the size of the device, A switch is inserted into it, connected between the output of the alternating voltage source and the input of the amplifier, and connected to a transceiver element made in the form of a rod-shaped piezoceramic Skog acoustic vibration transducer mounted with the possibility of sensing the vibrations excited outside them after reflection from the roll of the magnetic tape and changes its electromotive force by varying the number of turns of the coil of the magnetic tape. Sources of information taken into account during the examination 1. German patent number 1237353, cl. 42 g 18, 1967. 2. US patent number 3617132, cl. 356-156, 1971 (prototype).