CN2366906Y

CN2366906Y - Decode for goods soft labels including passive LC resonant circuit

Info

Publication number: CN2366906Y
Application number: CN 99206911
Authority: CN
Inventors: 李崇欣
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-04-29
Filing date: 1999-04-29
Publication date: 2000-03-01
Anticipated expiration: 2009-04-29

Abstract

The utility model provides a decoder for goods soft labels, which comprises a passive LC resonant circuit and is provided with a modulation signal circuit, a frequency modulation oscillation circuit, a high frequency amplification circuit and a folded dipole antenna. In addition, the output end of the high frequency amplification circuit is connected with the output end of a voltage boosting circuit and an NOR gate circuit is arranged between the frequency modulation oscillation circuit and the high frequency amplification circuit. The output end of the NOR gate circuit is connected with the high frequency amplification circuit, one foot of the input end of the NOR gate circuit is connected with the frequency modulation oscillation circuit and the other foot is connected with a negative sharp pulse circuit. The circuits are characterized in that when the emission power of frequency modulation signals is enhanced, the breakdown efficiency of the frequency modulation signals is enhanced at the same time. Thus, the utility model has the advantage that capacitance in soft labels can be effectively broken down.

Description

The demoder that comprises the soft label of commodity of Passive LC resonant circuit

The utility model relates to a kind of demoder that comprises the soft label of commodity of Passive LC resonant circuit.

The soft label of commodity that comprises the Passive LC resonant circuit is with the matching used a kind of high frequency reflecting plate of commodity wireless anti-theft alarming device, the natural frequency of this LC resonant circuit equals the modulation frequency of the frequency modulation transmitter emission in the alarm, when posting the commodity process cashier of the soft label of this commodity, cashier should be provided with a demoder that the electric capacity in the LC resonant circuit is punctured, only in this way, alarm is not just reported to the police when these commodity pass through alarm subsequently, the soft tag decoder of this commodity can design with reference to the circuit structure of frequency modulation transmitter, but the puncture rate of electric capacity is very low, and it is unreliable to use.

The purpose of this utility model provide a kind of can be to the commodity that comprise the Passive LC resonant circuit electric capacity in the soft label implement the soft tag decoder of commodity that effectively punctures.

Solution of the present utility model is that the output terminal of the same booster circuit of output terminal of high-frequency amplifier circuit connects, between modulating oscillation circuit is with high-frequency amplifier circuit, be provided with OR-NOT circuit, the output terminal of this OR-NOT circuit connects with high-frequency amplifier circuit, one pin of input end connects with modulating oscillation circuit, and another pin connects with negative spike pulse circuit.

The main points of above-mentioned technical solution have two, the one, boost to the FM signal after the high frequency amplification, improve the emissive power of FM signal, reach the purpose of effective puncture electric capacity, the 2nd, introduce negative spike pulse signal, and make high-frequency signal concentrate the spike pulse part that appears at intermittence, like this, both reduced interference to other match appliance, shorten the running time of components and parts in the high-frequency amplifier circuit again, thereby improved the power factor of circuit, this shows, the soft tag decoder of commodity with above-mentioned technical characterictic can be implemented effectively to puncture to the electric capacity in the soft label of commodity, can guarantee the rationality of circuit design simultaneously again.

Illustrate particular content of the present utility model below in conjunction with drawings and Examples.

Fig. 1: frame principle figure of the present utility model;

Fig. 2: the circuit theory diagrams of the utility model embodiment.

As shown in the figure, the utility model is based on and designs on the basis of modulating emission circuit, modulating emission circuit has modulating signal circuit I, modulating oscillation circuit II, high-frequency amplifier circuit III and folded dipole antenna IV, the utility model connects the output terminal of the same booster circuit V of the output terminal of high-frequency amplifier circuit III, is provided with OR-NOT circuit IC between modulating oscillation circuit II is with high-frequency amplifier circuit III ₈, IC ₉, this OR-NOT circuit IC ₈, IC ₉Output terminal connect with high-frequency amplifier circuit III, a pin of input end connects with modulating oscillation circuit II, another pin connects with negative spike pulse circuit VI.High frequency transmission circuit has a lot of known circuit structures, and present embodiment adopts two-stage calculation amplifier IC ₁, IC ₂Form modulating signal circuit I, adopt voltage controlled oscillator IC ₃Make modulating oscillation circuit II, adopt the push-pull circuit of forming by triode Q and field effect transistor T to make high-frequency amplifier circuit III; Negative spike pulse circuit VI also has a lot of circuit structures, and the negative spike pulse circuit of present embodiment is by square wave generation IC circuit ₄, differentiating circuit C, R, not circuit IC ₅, NAND gate circuit IC ₆With diode D ₁Form; The effect of booster circuit V is to boost to the high-frequency signal that high-frequency amplifier circuit III exports, and present embodiment adopts integrated booster circuit IC ₇, rectification circuit D ₂Form booster circuit V; The principle of work of a whole set of circuit is to use operational amplifier IC ₁, IC ₂The triangular modulation voltage controlled oscillator IC that produces ₃Produce FM signal, pass through OR-NOT circuit IC again ₈, IC ₉Negative spike pulse modulation produce FM signal intermittently, and amplify and booster circuit V is launched by folded dipole antenna IV after boosting through push-pull circuit, when the soft label of the commodity that contain the Passive LC resonant circuit receives the electric capacity that just is enough to effectively puncture when transmitting in the LC resonant circuit, make the soft label of commodity lose reflex and lost efficacy.

Claims

1, a kind of demoder that comprises the soft label of commodity of Passive LC resonant circuit, have modulating signal circuit, modulating oscillation circuit, high-frequency amplifier circuit and folded dipole antenna, it is characterized in that: the output terminal of the same booster circuit of output terminal (V) of high-frequency amplifier circuit (III) connects, and is provided with OR-NOT circuit (IC between the same high-frequency amplifier circuit of modulating oscillation circuit (II) (III) ₈, IC ₉), this OR-NOT circuit (IC ₈, IC ₉) the same high-frequency amplifier circuit of output terminal (III) connect, the same modulating oscillation circuit of a pin (II) of input end connects, another pin connects with negative spike pulse circuit (VI).