CN2284981Y - Theft-proof alarm for carried articles - Google Patents

Abstract

The utility model relates to a theft-proof alarm for carried articles, which is composed of a radio transmitter and a receiver, wherein, the transmitter utilizes the crystal frequency stabilization and the narrow pulse modulation; the receiver adopts the superheterodyne reception. The local oscillation is the crystal frequency stabilization. The transmitter and the receiver are all provided with current limiting resistors to make the transmitter and the receiver have micro power consumption when in watch state. Magnetic antennas of the transmitter and the receiver are vertically installed in a casing; the top end of the casing is connected with short chains or nylon ropes for suspension.

Description

The anti-burglar alarm that loses of belongings

The utility model relates to the anti-burglar alarm that loses of a kind of belongings, and it comprises radio transmitter and receiver two parts.

Prior art is seen Chinese patent " the anti-prompting machine that the loses " patent No.: pocket antitheft, the anti-lose alarm of " 93213969,8, " wireless remote control " patent No. " 93233740.3 " numerical coding wireless reminding device " patent No. " 94237147.X " etc.Some technical schemes are provided, because wireless transmit, the receiver of these schemes do not adopt crystal frequency stabilization and receiver section to adopt superregeneration to amplify bar none simultaneously, wave detector, job insecurity has again, receiver in these schemes all compares power consumption, be necessary for receiver power switch is set, so just give user, the user who particularly travels outside, use makes troubles, promptly may be owing to forget that opening switching surface makes alarm not bring into play effect.

The purpose of this utility model is in order to overcome the weak point of above-mentioned technology, to provide a kind of emission, receiver frequency all very stable, and power consumption is small, the anti-burglar alarm that loses of belongings easy to use.

Task of the present utility model is finished like this, radiating portion is made of serial connections such as the little burst pulse modulating oscillator of dutycycle, crystal carrier-frequency oscilaltor, buffer amplifier, power amplifier and antenna loops, wherein burst pulse modulating oscillator, crystal carrier-frequency oscilaltor and buffer amplifier are finished by a slice integrated circuit, its positive power source terminal and powered battery end are serially connected with a current-limiting resistance, make foregoing circuit be operated in little power consumption, working current is tens microamperes only.Receiver by receiving antenna loop, two-stage height put, put in the one-level mixing, two-stage, transistor detection, shaping time-delay and news ring the circuit serial connection and constitute, wherein local oscillation also adopts the crystal frequency stabilization, among the intermediate frequency F=F connects-F sends out.Also be connected a current-limiting resistance at two integrated circuit positive power source terminals respectively with the powered battery positive power source terminal, reduce complete machine and wait for electric current, can save power switch like this.The receiver height is put between output terminal and the ground and is connected to amplitude limiter circuit, and large-signal is carried out amplitude limit, improves strong signal-selectivity.

The utility model working stability, power consumption are very little, and user's operation is very easy, selects reasonable carrier frequency and bandwidth for use, and antijamming capability is very strong.Can several groups work simultaneously and interference-free.

Below in conjunction with legend the utility model is done specific descriptions:

Fig. 1, the utility model transmitter electrical schematic diagram;

Fig. 2, the utility model receiver electrical schematic diagram;

Fig. 3, the utility model outside drawing;

Fig. 1 is the anti-transmitters that lose burglar alarm of belongings, (1) is narrow-pulse generator, its output is joined by the input end of diode D2 and crystal oscillator (2), crystal oscillator is modulated, the signal of modulator drives power discharging transistor N1 through inverter ic 1:B, IC1:C, IC1:D shaping, and the carrier signal after will modulating by antenna loop is at last launched.Resistance R 6 is serially connected between battery positive power source terminal and IC1 and the VCC, reduces the working current of IC1, and the value of adjusting R3 can change the pulse oscillator dutycycle, has reduced the average power consumption of power amplifier equally.

Fig. 2 is the anti-receivers that lose burglar alarm of belongings, (1) is local oscillation circuit, be connected to crystal TJ in this oscillation circuit oscillation frequency is carried out frequency stabilization, the two-stage High Amplifier Circuit by 4007, R2, C12, R16 form, be connected to the amplitude limiter circuit that limiter diode D3, D4 constitute by capacitance C13 between its output terminal 3Y and the ground, large-signal is carried out amplitude limit, improve the large-signal selectivity.Mixting circuit is made up of pipe of the NMOS among the IC1 (model is 4007) and resistance R 3, and the drain electrode 1DN of this NMOS pipe and LC loop L2, C6 join, and detect intermediate-freuqncy signal.(2) be to put in the two-stage, the 1DN of its input end and IC1 joins.(3) be the transistor detecting circuit, the output terminal of the input end of this circuit and (2) joins, and amplifies and detects narrow pulse signal, cushion to E1 through IC2:F and to charge, (5) be that news are rung circuit, its sounding component adopts three end piezoelectric buzzers, when receiver is received the narrow pulse signal of transmitter, level on the E1 is high, (5) do not work, when transmitter high receiver far away, when receiver can not receive the signal of transmitter, level on the E1 is a low level, and (5) are with the output alarm sound.Positive power source terminal at IC1 and IC2 is connected in series current-limiting resistance R13, the R15 positive power source terminal VDD to battery respectively, adjusts these two resistance and can make operation of receiver at little power consumption state.

(1) among Fig. 3 is a magnetic antenna, and (2) are minicell, and (3) are printed board, and (4) are casing, and (5) are metallic bond (nylon rope).In order to overcome the directivity of magnetic rod antenna, the magnetic antenna of emission of the present utility model, receiver all is vertically mounted in the casing, and the shell top is connected to the short chain (nylon rope) that is used to hang, this chain can be suspended on one's body belongings or the owner, no matter how belongings or human body tilt, because the effect of gravity can make two machine magnetic rod antennas remain parallel.

The utility model is owing to adopt above design, and working stability is selected the different crystal of frequency, just can organize simultaneously more and use, and is noiseless mutually.Power consumption is very low when waiting for, and can save power switch, avoids the user because of forgetting that opening switch can't play a role alarm, and operation is easier, easily row.

Claims (3)

1, a kind ofly be it is characterized in that by the anti-burglar alarm that loses of radio transmitter and receiver belongings dimerous: radiating portion is by the burst pulse modulating oscillator, the crystal carrier-frequency oscilaltor, buffer amplifier, serial connection such as power amplifier and antenna loop constitutes, burst pulse modulating oscillator wherein, crystal carrier-frequency oscilaltor and buffer amplifier are finished by a slice integrated circuit, its positive power source terminal and battery positive power source terminal are serially connected with a current-limiting resistance, make foregoing circuit be operated in little power consumption, receiver is by the receiving antenna loop, the two-stage height is put, the one-level mixing, put in the two-stage, the transistor detection, shaping time-delay and news are rung the circuit serial connection and are constituted, wherein local oscillation also adopts the crystal frequency stabilization, also be connected current-limiting resistance at two integrated circuit positive power source terminals respectively with the battery positive power source terminal, the receiver height is put between output terminal and the ground and is connected to amplitude limiter circuit.

2, the anti-burglar alarm that loses of the described belongings of root a tree name claim 1, it is characterized in that: receiver two-stage height is put by two phase inverters in 4007 and R2, C12, R16 and is formed, and mixting circuit is made up of the nmos pass transistor in the integrated circuit 4007, resistance R 3 and frequency-selective circuit L2, C6.

3, the anti-burglar alarm that loses of root a tree name claim 1,2, described belongings is characterized in that launching, the magnetic antenna of receiver all is vertically mounted in the casing, and the shell top is connected to short chain or the nylon rope that is used to hang.

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