CN2403000Y

CN2403000Y - Magnetic head

Info

Publication number: CN2403000Y
Application number: CN 99206991
Authority: CN
Inventors: 林书文
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-05-17
Filing date: 1999-05-17
Publication date: 2000-10-25
Anticipated expiration: 2009-05-17

Abstract

The utility model relates to a detecting magnetic head for weak magnets and ferromagnetic moving bodies. The utility model is formed by that permanent magnet sheets (2) with high magnetic properties are additionally arranged on the surface of an ordinary audio magnetic head (1), from which a guide frame and an installing support frame are taken off, of a housing made of ferromagnetic material. A constant and actual magnetic bias voltage is made to exist at the position of a magnetic head gap, so that the magnetic head has the characteristic that the detecting sensitivity is increased. The utility model can be used for the discrimination of bills, trade mark anti-forgery marks and paper money which are formed by magnetic ink printing, the fabrication of distant approach switches, etc.

Description

Magnetic head

The utility model relates to a kind of detection magnetic head to weak magnetic object and ferromagnetic moving object, especially manufactures shell by ferromagnetic material, takes down weak magnetic object and the ferromagnetic moving object that the ordinary audio magnetic head transformation of the way of tape saddle and mounting bracket forms and detects magnetic head.

The commercially available detection magnetic head to weak magnetic object and ferromagnetic moving object is exactly this structure at present, mainly is made up of coil, soft magnetic material iron core, keeper, ferromagnetic material shell, casting glue etc.When weak magnetic object or ferromagnetic moving object process magnetic head aperture, the magnetic line of force enters the magnetic head iron core by the magnetic head slot, make that the vicissitudinous magnetic line of force passes through in the iron core, so in coil, induce the electromotive force of variation, the electromotive force of this variation just amplified and can detect weak magnetic object or ferromagnetic moving object.The flat detect counterfeit money machine of selling on the market is made of this class magnetic head now.But, magnetic head detects the tape sound signal because being originally to be exclusively used in, its iron core aperture can not be added with magnetic biasing and press, otherwise will erase the sound signal on the tape, thereby when magnetic head being used for to weak magnetic object or ferromagnetic moving object detection, sensitivity is low, the circuit cost height, detected material body image tape equally will be pressed on the friction of magnetic head aperture simultaneously could reflect signal.Result of use is relatively poor.

Task of the present utility model provides a kind of detection magnetic head to weak magnetic bodies and ferromagnetic moving object, and it highly sensitive can be realized high up in the air the detection with ball bearing made using.

For solving above-mentioned task, the utility model is realized by following measure: made shell by ferromagnetic material, the surface that takes down the ordinary audio magnetic head of tape saddle and mounting bracket adds high magnetic permanent magnet sheet, makes space, magnetic head aperture exist a constant magnetic biasing to press.When detected weak magnetic object or ferromagnetic moving object during near the magnetic head aperture, former constant the changing of magnetic biasing Hair Fixer that adds of iron core, coil on the iron core just induces the electromotive force of variation, the electromotive force of this variation is amplified, just can be detected weak magnetic object or ferromagnetic moving object.

Because above-mentioned measure is only to make shell by ferromagnetic material, the surface that takes down the ordinary audio magnetic head of tape saddle and erecting frame adds high magnetic permanent magnet sheet, makes space, magnetic head aperture exist a constant magnetic biasing to press to realize.It is highly sensitive, and cost is low, only just can realize detection high up in the air to weak magnetic object and ferromagnetic moving object with simple circuit.

Below in conjunction with accompanying drawing the utility model is elaborated.

Accompanying drawing is the side view of an embodiment of the present utility model.

In the accompanying drawings, a pair of high magnetic circular permanent magnet sheet [2] magnetic pole is attached to respectively by ferromagnetic material and makes shell, takes down the bottom on ordinary audio magnetic head [1] surface of tape saddle and mounting bracket, has not only improved sensitivity but also has made things convenient for the application assembling of magnetic head.

Certainly, high magnetic round permanent magnet sheet [2] also can stick on two other surface of above-mentioned ordinary audio magnetic head [1], also can stick on the outside surface of above-mentioned ordinary audio magnetic head [1] with non-circular body permanent magnet sheet.

Claims

The detection magnetic head to weak magnetic object and ferromagnetic moving object that a kind of audio head of being made up of coil, soft magnetic material iron core, keeper, ferromagnetic material shell, casting glue [1] and permanent magnet sheet [2] are made is characterized in that: the magnetic head aperture exists a constant magnetic biasing to press.