CN2190383Y - Alarm for preventing fraudulent use of telephone terminal - Google Patents

Abstract

The utility model relates to a telephone terminal alarm belongs to the communication field, has polarity selection circuit, detection circuitry, warning circuit, suppression circuit and suppression circuit control switch in the telephone terminal alarm. The utility model discloses a detect telephone circuit's voltage variation, can take precautions against effectively and steal the phone through wired or wireless mode, when sending audible and visual alarm, the exhalation of automatic suppression phone, therefore can be extensive be applied to the phone user.

Description

Alarm for using telephone illegally

The utility model relates to a kind of telephone terminal alarm, belongs to the communications field.

Along with being on the increase of economic and society's contact, the thing of utilizing Wireline in the communications field, adopt and connecing mode or adopt radio wave intercepting and capturing pin mode illegally to usurp phone often has generation, upset normal communication contact, made the user suffer the tremendous economic loss.The present precautionary measures can only adopt locking method to control on telephone set, and on telephone line or adopt the radio wave mode to usurp just powerless.

Task of the present utility model provides a kind of device that can suppress illegally to usurp under the wired or wireless state phone effectively.Can in time send sound and light alarm and can suppress its exhalation all the illegal usage behaviors beyond non-the machine.

Task of the present utility model is to realize like this, a kind of shell that comprises, the anti-alarm of usurping of the telephone terminal of power supply rectifier and voltage regulator circuit and power supply indication, it is characterized in that also having polarity selecting circuit in the alarm, testing circuit, warning circuit, suppress circuit and suppress circuit controling switch, input at power supply is serially connected with K switch, diode D1～D4 forms polarity selecting circuit, resistance R 2, R3, R1, triode BG2 forms testing circuit, ic chip 2(4093), resistance R 6, R5, capacitor C 2, C1, piezo-electric ceramic sounding sheet HTD forms warning circuit, resistance R 8, R _PR7, capacitor C 3, diode D5, relay J and ic chip 3(555) form and suppress circuit, resistance R 4, R9, triode BGI and indicator light LED form and suppress circuit controling switch, the output of polarity selecting circuit is connected with an end of resistance R 1 in the testing circuit, in the testing circuit collector electrode C of three utmost point BG2 respectively with warning circuit in ic chip 2(4903) first pin be connected, be connected with an end of resistance R 4 in the inhibition circuit controling switch, suppress ic chip 3(555 in the circuit) the 4th, 8 pin, resistance R 7 is connected with the emitter e of triode BG1 in suppressing circuit controling switch, and mains switch K and inhibition indicator light LED are fixed on the shell.

The utility model is by detecting the change in voltage of telephone circuit, can take precautions against effectively and usurp phone, can send sound and light alarm on the one hand, can suppress phone on the other hand automatically and breathe out by wired or wireless mode, do not increase simultaneously the telephone line load, do not influence incoming call yet.Weak point of the present utility model is when the phone user uses phone, needs to cut off K switch, and circuit is quit work, in order to avoid false alarm suppresses.

Accompanying drawing is the utility model electrical schematic diagram.

In the accompanying drawing: diode D1～D5, triode BG1, BG2, ic chip 1, IC2, IC3, resistance R 1～R9, capacitor C 1～C3, LED, relay J, K switch, potentiometer Rp, piezo-electric ceramic sounding sheet HTD, subscribers feeder L1, L2.

Further specify the utility model in conjunction with the accompanying drawings and embodiments.The anti-alarm of usurping of telephone terminal is a transducing signal to detect telephone subscriber line voltage, and the input of polarity selecting circuit is connected to telephone loop L1, L2.When static, cut because telephone line is empty, 60V voltage on its circuit makes detecting gate triode BG2 conducting through R1, R2 dividing potential drop, its C utmost point is low level, triode BG1 ends, suppress circuit and do not work, simultaneously ic chip 2(4093) in the 3rd pin of YF1 be high level, be low level through the anti-phase YF3 of making control end 8 pin of YF2; 3 pin high level give capacitor C 1 charging by resistance R 5 again, make 2 pin of YF1 be high level.When the appropriator off-hook, line voltage distribution is dropped to about 12V by 60V, the b utmost point of triode BG2 is low level, BG2 ends, its C utmost point becomes high level, ic chip 2(4093) the 3rd pin output low level of the YF1 in, be high level through anti-phase the 8th pin that makes of YF2, thereby make sounder vibration sounding, and the voltage on the capacitor C 1 discharges by resistance R 5 when the 3rd pin low level of YF1, make YF1 output high level, after YF2 was anti-phase, the 8th pin of YF3 was low level, and the sounder failure of oscillation is sounding not, the high level of YF1 output gives capacitor C 1 charging by resistance R 5 again, make YF1 output low level again, make sounder vibration sounding after anti-phase, so circulation, make alarm become sounding at very brief intermittence.When triode BG2 ends, the b utmost point of triode BG1 is high level, and makes triode BG1 conducting, and the LED that is fixed on the shell is lighted, suppressing circuit connection operating voltage starts working, supply voltage gives capacitor C 3 chargings by resistance R 8, Rp, R7, this moment ic chip 3(555) the 3rd pin output high level, the relay J adhesive, normally opened contact J1-1 connects, subscribers feeder L1, L2 have been suppressed telephone loop by short circuit, and appropriator can't be used; When capacitor C 3 is charged to 2/3 operating voltage, capacitor C 3 is by the latter half and the ic chip 3 internal discharge tube discharges of resistance R 8, Rp, this moment, its 3rd pin was low level, relay J discharges, J1-1 disconnects, and detects the appropriator on-hook of whether having taken out stitches for detecting gate triode BG2 and makes voltage return back to 60V.As not replying, then when capacitor C 3 by resistance R 8, when Rp the latter half is discharged to operating voltage 1/3, the discharge tubes in the ic chip 3 cut out, capacitor C 3 is recharged once more, the 3rd pin of IC3 is exported high level again and is made relay J adhesive inhibition telephone line; When detecting telephone line voltage and return back to 60V, triode BG2 conducting, collector electrode C output low level, reporting to the police and suppressing circuit all reverts to static state, and telephone line is not affected.The capacity of adjustment capacitor C 3 and resistance R 7, the big I of Rp resistance change the charge constant of capacitor C 3, thereby change the relay J length of pickup time, regulate Rp scalable duty ratio, thereby adjust the time scale of relay J adhesive and disconnection.

Claims (1)

1, a kind of shell that comprises, the anti-alarm of usurping of the telephone terminal of power supply rectifier and voltage regulator circuit, it is characterized in that anti-the usurping of telephone terminal also has polarity selecting circuit in the alarm, testing circuit, warning circuit, suppress circuit and suppress circuit controling switch, input at power supply is serially connected with K switch, diode D1-D4 forms polarity selecting circuit, resistance R 2, R3, R1, triode BG2 forms testing circuit, ic chip 2 (4093), resistance R 6, R5, capacitor C 2, C1, piezo-electric ceramic sounding sheet HTD forms warning circuit, resistance R 8, R9, R7, capacitor C 3, diode D5, relay J and ic chip 3 (555) are formed and are suppressed circuit, resistance R 4, R9, triode BG1 and indicator light LED form and suppress circuit controling switch, the output of polarity selecting circuit is connected with an end of resistance R 1 in the testing circuit, the collector electrode C of triode BG2 is connected with first pin of ic chip 2 (4903) in the warning circuit respectively in the testing circuit, with suppress circuit controling switch in an end of resistance R 4 is connected, in the inhibition circuit the 4th of ic chip 3 (555) the, 8 pin, resistance R 7 is connected with the emitter e of triode BG1 in suppressing circuit controling switch.