CN201255889Y

CN201255889Y - Degaussing device for anti-theft electronic label

Info

Publication number: CN201255889Y
Application number: CNU2008201207786U
Authority: CN
Inventors: 王勇; 邱慎产
Original assignee: Hangzhou Century Co Ltd
Current assignee: Beijing Sichuang puriton Technology Development Co. Ltd.
Priority date: 2008-07-02
Filing date: 2008-07-02
Publication date: 2009-06-10
Anticipated expiration: 2018-07-02

Abstract

The utility model provides a degaussing apparatus for anti-theft electronic tags, which comprises a degaussing and emission receiving coil, a resonant capacitor serially connected with the coil, a current zero cross detection circuit for the coil, and a direct current charge circuit and a direct current discharge circuit for an energy storage capacitor, a connecting circuit connected with an emission power supply, a switch provided on the charge circuit of the energy storage capacitor, a charge switch and a discharge switch which are parallel connected with the resonant capacitor, wherein the connecting circuit connected with the emission power supply is parallel connected with the discharge circuit of the energy storage capacitor and is connected with the charge switch, the connecting circuit connected with the emission power supply is provided with an emission switch, the discharge circuit of the energy storage capacity is provided with a discharge degaussing switch, the joint connected with the emission power supply, the charge power supply, the resonant capacitor and the coil are serially connected with a diode group therebetween. The degaussing apparatus has low cost, small volume, low power consumption, low heat generation, continuous operation for long time, and eliminated effect and interference in operation on the power supply of power network.

Description

The degaussing gear of theft-proof electron label

Technical field

The utility model relates to a kind of degaussing gear of theft-proof electron label.

Background technology

The degaussing gear that is used for the market anti-theft tag in the past mainly is divided into two classes:

First kind product: coil quantity is many, need to be equipped with anti-magnetized coil and emission receiving coil, technology and circuit control are complicated, and the anti-magnetized coil number of turns is many, volume is big, need to be equipped with specific silicon sheet core, require and the very high demagnetization capacitor of cost, thermal value and power consumption are big, product can not long time continuous working, and general continuous demagnetization will enter superheat state about 1 minute.During demagnetization mains supply had certain influence and interference.Second series products: emission receives the shared one group of coil of demagnetization, its demagnetization adopts storage capacitor disposable to coil discharge, free oscillation and form erasing field in the resonant tank formed by storage capacitor and anti-magnetized coil again of this energy then, the shortcoming of this kind mode is that free-running number of times is few, the forward and reverse erasing field strength difference that forms is too big, disposable erasure effect is poor, exists product to need secondary or the above demagnetization of secondary or shortcoming that very closely demagnetization just can be successful.

Summary of the invention

Technical problem to be solved in the utility model provides the degaussing gear of the theft-proof electron label of the simple low cost of manufacture of a kind of circuit.For this reason, the utility model is by the following technical solutions: it comprises demagnetization and emission receiving coil, and the resonant capacitance of connecting with coil, the current over-zero testing circuit of coil, described degaussing gear also comprises the dc charging circuit and the discharge circuit of storage capacitor, described degaussing gear also is provided with the connecting circuit that is connected with emission power, on the charging circuit of described storage capacitor switch is set, resonant capacitance connects charge switch and discharge switch in parallel, the connecting circuit that is connected with emission power is connected with charge switch with the discharge circuit of storage capacitor is in parallel, the connecting circuit that is connected with emission power is provided with emission switch, the discharge circuit of storage capacitor is provided with the discharge field-breaking switch, the described contact that is connected with emission power and and charge power supply, the button bit diode group of connecting between resonant capacitance and the coil.Owing to adopt the technical solution of the utility model, the utlity model has following advantage:

1. the emission of collection signal, reception and demagnetization are one, a shared small coil, and its weight only is about 1/20 of existing product coil weight, volume is little;

2. adopt the self-excitation resonance mode to obtain demagnetization alternation heavy current and demagnetization high-intensity magnetic field, need not specific iron core and specific demagnetization electric capacity, so volume is little, in light weight;

3. because anti-magnetized coil is little, each erasing time short (about 200ms), therefore low in energy consumption, thermal value is little, can work long hours continuously;

Since the demagnetization heavy current by electric capacity storing energy abrupt release gained in the product, and electric capacity when charging electric current is little, so mains supply is not had any harmful effect and interference during product work;

5. low cost of manufacture.

Description of drawings

Fig. 1 is the circuit theory diagrams of embodiment that the utility model provides.

Embodiment

With reference to accompanying drawing.The utility model comprises demagnetization and emission receiving coil L, and the resonant capacitance C2 that connects with coil L, the current over-zero testing circuit of coil L, described degaussing gear also comprises dc charging circuit 1 and the discharge circuit 2 of storage capacitor C1, described degaussing gear also is provided with the connecting circuit 3 that is connected with emission power 5, K switch 1 is set on the charging circuit of described storage capacitor C1, resonant capacitance C2 connects charge switch K3 and discharge switch K4 in parallel, the discharge circuit of connecting circuit that is connected with emission power and storage capacitor C1 is in parallel to be connected with charge switch K3, the connecting circuit that is connected with emission power is provided with emission switch K5, the discharge circuit of storage capacitor C1 is provided with discharge field-breaking switch K2, the described contact that is connected with emission power and and charge power supply, the button bit diode group of connecting between resonant capacitance C2 and the coil L.

Diode D3 is set on the dc charging circuit, and the charge power supply 4 that dc charging circuit connected can be direct supply or alternation or full wave power supply, and emission power is a direct supply.

Charging storage capacitor C1 is made of electric capacity or many electric capacity in parallel.

K switch 1, K2, K3, K4, K5 switch can be triode, field effect transistor, the multiple electronic switch that electron devices such as controllable silicon are formed.

Current over-zero testing circuit 1 can adopt existing custom circuit.

During work:

1.K2 close, K1 opens, charge power supply is to charging storage capacitor C1 charging.

2.K1K4K5 disconnection, K2K3 closure, electric current, forms the weak forward that grows from weak to strong and increases progressively the magnetic field of successively decreasing resonant capacitance C2 charging through K2, K3 among the charging storage capacitor C1 on coil L.

3.K1K3K5 disconnect, the K2K4 closure, resonant capacitance C2 and coil be L shaped to be become closed-loop path, resonant capacitance C2 to go up storage electric weight flowing through coil L to form the weak magnetic field of successively decreasing that oppositely increases progressively that grows from weak to strong on coil L.

4. the circuit of resistance R and current over-zero testing circuit composition is to carrying out the current over-zero detection because resonant capacitance C2 discharges and recharges the electric current that forms in coil L, reach based on this signal K3, K4 switch are controlled, the resonant circuit of setting up resonant capacitance C2 and coil L composition carries out effective self-excitation resonance, make coil L produce powerful forward and reverse alternation erasing field, its resonance energy derives from storage capacitor C1.

5.K1 closed pair storage capacitor C1 is full of specified electric quantity, K1 disconnects then, K2 is closed under erase signal control, K3 closed pair resonant capacitance C2 coils L charging this moment, send signal controlling K3 by the current over-zero testing circuit after charging finishes and disconnect the K4 closure, resonant capacitance C2 is by coil L discharge, control the K3 closure by the current over-zero testing circuit again behind the resonant capacitance C2 discharge off, K4 disconnects and by storage capacitor C1 resonant capacitance C2 being charged once more, form the resonant circuit that resonant capacitance C2 and coil L form thus and produce strong self-excitation resonance, till this process lasts till that always storage capacitor C1 goes up the electric weight that stores and put.

6. after storage capacitor C1 storage power had been put, K2 disconnected, the K1 closure, and charge power supply is charged once more to storage capacitor C1, for demagnetization is ready successively down.

7.K2 disconnect, emission power is through the K5 closure, by alternately opening and closing of K3, K4 resonant capacitance C2 is discharged and recharged, on coil L, form the emission alternating magnetic field of characteristic frequency, work with excited electrons label (EAS), the button bit diode group that diode D1, D2 form is electronic tag (EAS) point detection signal at itself and coil L tie point 6 places, puts with this and picks up the eas tag signal.

Claims

1. the degaussing gear of theft-proof electron label, it is characterized in that it comprises demagnetization and emission receiving coil (L), and the resonant capacitance (C2) of connecting with coil (L), the current over-zero testing circuit of coil (L), described degaussing gear also comprises the dc charging circuit and the discharge circuit of storage capacitor (C1), described degaussing gear also is provided with the connecting circuit that is connected with emission power, switch (K1) is set on the charging circuit of described storage capacitor (C1), resonant capacitance (C2) connects charge switch (K3) and discharge switch (K4) in parallel, the discharge circuit of connecting circuit that is connected with emission power and storage capacitor (C1) is in parallel to be connected with charge switch (K3), the connecting circuit that is connected with emission power is provided with emission switch (K5), the discharge circuit of storage capacitor (C1) is provided with discharge field-breaking switch (K2), the described contact that is connected with emission power and and charge power supply, the button bit diode group of connecting between resonant capacitance (C2) and the coil (L).

2. the degaussing gear of theft-proof electron label as claimed in claim 1 is characterized in that connection line between described button bit diode group and the coil (L) is provided with the tie point with the signal deteching circuit of theft-proof electron label.

3. the degaussing gear of theft-proof electron label as claimed in claim 1 is characterized in that storage capacitor (C1) is made of electric capacity or many electric capacity in parallel.