CN2249947Y - Permenant magnet pick-up - Google Patents

Abstract

The utility model relates to a permanent magnet head which is formed by bonding a recording and playing magnet head (1) or any nonmagnetic magnet head and a permanent magnet piece (2). The utility model has high induction sensitivity and high input signal-to-noise ratio when the utility model is used as a magnetic detection sensor of a magnetic false money identifying instrument. The utility model has the advantages of easy manufacture and good performance. Simultaneously, the utility model can be used as a magnet sensor in other fields.

Description

A kind of permanent magnetism magnetic head

The utility model relates to a kind of permanent magnetism magnetic head with magnetic.

Bank note magnetic detection false distinguishing instrument, must be furnished with one or more magnetic heads as the magnetic detection sensor, when genuine note passed through magnetic head, the magnetic printing material on the genuine note made magnetic head induce electric signal, this signal shows or differentiates true and false banknote after subsequent conditioning circuit amplifies.As can be seen, the induction sensitivity of magnetic head, be decided by to detect the complete machine performance of false distinguishing instrument.Existing reproducers head on the current market, when the magnetisable material on the detection genuine note since the usefulness, its weak output signals, signal to noise ratio are very low, so that can't differentiate the signal that its genuine note is responded to.So this class magnetic head is not selected.When making manual magnetic false distinguishing instrument, the higher reproducers head of the sensitivity of selecting for use is arranged also but machine sensitivity is still lower so that in use with firmly scouring on magnetic head of banknote, be easy to make nominal value to damage.For the magnetic detection false distinguishing instrument that is used on the paper money counter, require the induction sensitivity of magnetic head higher, thereby must manufacture and design special-purpose magnetic head, this special-purpose magnetic head costs an arm and a leg, induction sensitivity neither be very high, above-described playback head and special-purpose magnetic head all belong to nonmagnetic magnetic head, that is to say at nonmagnetic material during near magnetic head the no magnetic field of magnetic head itself.The induction sensitivity that experiment showed, this nonmagnetic magnetic head is lower, and when selecting this magnetic head for use, thereby the amplification quantity of its follow-up amplifying circuit requires to make greatly the output signal to noise ratio low, and long-time stability are poor, and the false distinguishing accuracy is affected.

The purpose of this utility model will provide a kind of novel permanent magnetism magnetic head exactly, that is to say that this permanent magnetism magnetic head itself just exists permanent-magnetic field.The induction sensitivity that experiment showed, this permanent magnetism magnetic head is much higher than nonmagnetic magnetic head, input signal to noise ratio height, and the amplification quantity of follow-up amplifying circuit needn't be very big, and long-time stability are good, and false distinguishing is reliable.This permanent magnetism magnetic head is highly suitable for the magnetic sensor of manual magnetic fake-identifying instrument and paper money counter DYNAMIC MAGNETIC fake-identifying instrument.

The purpose of this utility model is achieved in that at common videocorder tape record head or other and belongs on the shell of nonmagnetic magnetic head, sticking lastblock (or more than) permanent magnet pieces, this flat thin magnet just makes whole magnetic head have permanent-magnetic field, preceding magnetic gap place at magnetic head has also formed a permanent-magnetic field, and this has just constituted external magnetic type permanent magnetism magnetic head.And with flat thin magnet (when manufacturing magnetic head) or be bonded on the conducting magnet core of magnetic head when manufacturing conducting magnet core with permanent magnet, this has just constituted internal magnetic type permanent magnetism magnetic head.

The concrete structure of utility model is provided by following examples and accompanying drawing thereof.

Fig. 1 is the structural drawing according to the external magnetic type permanent magnetism magnetic head that the utility model proposes.

Fig. 2 is according to the internal magnetic type permanent magnetism magnetic head structure figure that the utility model proposes.

Describe concrete structure of the present utility model in detail below in conjunction with accompanying drawing.

Shown in the accompanying drawing 1, be external magnetic type permanent magnetism magnetic head of the present utility model.This magnetic head comprises a common reproducers head (1), (or more than an one) permanent magnet pieces (2), shell (3) and signal output cable (4) composition, wherein cement with bonding agent between reproducers head (1) and the permanent magnet pieces (2), in the shell (3) of then it being packed into.Signal output cable (4) has two lines, and wherein one is soldered on the shell of magnetic head (1) for shielding wire, the one head is welded to an output pin of magnetic head (1) simultaneously again, and another is signal wire, it is soldered on another output pin of magnetic head (1).The external magnetic type of above version forever the property magnetic head, be highly suitable for dynamic paper money counter magnetic false distinguishing instrument; And on being used for manual magnetic fake-identifying instrument the time, only need to go up, permanent magnet pieces (2) is cemented with bonding agent at common reproducers head (1), then it is soldered directly on the circuit board.As can be seen from Figure 1, because the sticking permanent magnet pieces (2) of the shell of reproducers head (1), go up at its reproducers head (1) like this and form a permanent-magnetic field, and also there is a permanent-magnetic field at the magnetic gap place of reproducers head (1) when any magnetisable material or have the magnetic field intensity of magnetic bodies by the magnetic gap place of reproducers head (1) and will change, thereby produces signal voltage in the coil of reproducers head (1).

Shown in the accompanying drawing 2, be internal magnetic type permanent magnetism magnetic head of the present utility model.This magnetic head is that a slice or the above permanent magnet pieces of a slice (6) are adhered on its conducting magnet core (5), makes its magnetic gap place have permanent-magnetic field.If when manufacturing reproducers head (1), clip permanent magnet pieces in its conducting magnet core (5) or all manufacture with permanent magnet pieces.The structure of this internal magnetic type permanent magnetism magnetic head is more simple.

Claims (4)

1, is suitable for a kind of permanent magnetism magnetic head that bank note magnetic fake-identifying instrument is used, this magnetic head is bonded by reproducers head (1), permanent magnet pieces (2), it is characterized in that going up sticking (or more than an one) permanent magnet pieces (2) or (6), make its magnetic gap place form a permanent-magnetic field at reproducers head (1) at reproducers head (1).

2, permanent magnetism magnetic head according to claim 1 is characterized in that permanent magnet pieces (2) directly is bonded on the shell of reproducers head (1) or any nonmagnetic magnetic head.

3, permanent magnetism magnetic head according to claim 1 is characterized in that permanent magnet pieces (6) directly is bonded on the conducting magnet core (5) of reproducers head or any nonmagnetic magnetic head.

4, permanent magnetism magnetic head according to claim 1 is characterized in that conducting magnet core (5) clips permanent magnet pieces or all manufactures with permanent magnet.