CN2245310Y - Device resisting stealing utilization of electricity for telephone line - Google Patents
Device resisting stealing utilization of electricity for telephone line Download PDFInfo
- Publication number
- CN2245310Y CN2245310Y CN 95233338 CN95233338U CN2245310Y CN 2245310 Y CN2245310 Y CN 2245310Y CN 95233338 CN95233338 CN 95233338 CN 95233338 U CN95233338 U CN 95233338U CN 2245310 Y CN2245310 Y CN 2245310Y
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- CN
- China
- Prior art keywords
- telephone line
- circuit
- resistance
- signal generating
- transistorized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Devices For Supply Of Signal Current (AREA)
Abstract
The utility model relates to an anti-theft device for telephone lines, composed of a bridge rectifier, a voltage dividing circuit, a composite switch circuit, a signal generating circuit, an amplifier tube and a photoelectric coupler. The anti-theft device adopts a self power supply system and few elements, and thus has small size, convenient installation and less power consumption. The utility model can effectively prevent the telephone from being stolen, can cause a stealing telephone not to be dialed for dual-audio or pulse dual-audio compatible telephone lines, and can be used for all telephone subscribers.
Description
The utility model relates to the anti-device of usurping of a kind of telephone line.
Stolen in order to prevent telephone line, the anti-device of usurping of various telephone lines has appearred, these prevent that usurping device can reduce three major types, a kind of is short-circuit type, another kind is the interfering noise formula, the former operation principle is when telephone line is stolen, and telephone line is short circuit, but this mode does not just reach the anti-effect of usurping when telephone line loop resistance value is big; The back is a kind of be telephone line when stolen alarm produce interfering noise, this method also is subjected to the restriction of telephone line loop resistance value, when loop resistance value one is big, interfering noise is attenuated, and usurps phone and still can speak up under interfering noise.Commercially available in addition telephone line prevents that usurping device also has following defective; The power supply of employing external power, palpus is differentiated the polarity of telephone line during installation, and volume is big etc.
The utility model aim to provide a kind of small and exquisite, must not additional power source, the easy for installation and reliable and practical anti-device of usurping of telephone line.
Road, amplifier tube and photoelectric coupling circuit take place by bridge rectifier, bleeder circuit, composite switch circuit, signal and form in the utility model.The bridge rectifier that is constituted by a diode is connected on the telephone line, usurps the device power supply for telephone line is anti-; Bleeder circuit is made of two resistance, is connected on the both positive and negative polarity of power supply after the series connection of two resistance.Composite switch circuit is made up of three PNP transistor, and first transistor base is connected on the dividing point of bleeder circuit, and its emitter just connects, and collector electrode connects negative on the one hand through resistance, link to each other with second transistorized base stage again in addition.Second transistorized emitter links to each other with the 3rd transistorized base stage, and the 3rd transistorized emitter just connects, and the collector electrode of second, third two pipe links to each other after a resistance inserts signal generating circuit.The signal generating circuit feeder ear connects voltage-stabiliser tube, also is connected with crystal oscillator simultaneously, and its output is connected with NPN type amplifier tube base stage through a current-limiting resistance.Photoelectricity lotus root and device and a current-limiting resistance and connect after be serially connected in the telephone line, wherein photoelectric tube is attempted by in the composite switch circuit on first transistorized collection, the emitter-base bandgap grading.
The utility model adopts the self-contained electric system power supply, and used element is few, and so volume is little, cost is low, and is easy for installation, and quiescent dissipation is little, and result of use is good, for double-tone frequently or the pulse double-tone compatibility is good frequently, telephone line can make to be usurped phone and can't dial.
Below in conjunction with accompanying drawing this utility model is done further narration.
Fig. 1 is the utility model circuit diagram; wherein bridge rectifier 3 can be connected on telephone line 1 and 2; it becomes telephone line self power supply into DC power supply is that the anti-device of usurping of telephone line is powered; resistance 4 and 5 constitutes bleeder circuit; dividing point is connected transistor 6 base stages; for it provides base voltage; transistor 6 collector electrodes connect negative through resistance 7; its emitter just connects; the emitter of transistor 8 links to each other with the base stage of transistor 9; the base stage of transistor 8 is connected on the collector electrode of transistor 6; the emitter of transistor 9 just connects; transistor 8 is connected with 9 collector electrode to be connected through resistance 10 and is its power supply on the signal generating circuit 12; transistor 6; 8 and 9 and resistance 7 form composite switch circuits; voltage-stabiliser tube 11 is connected the feeder ear of signal generating circuit 12 so that protection to be provided; signal generating circuit 12 connects crystal oscillator 13; its output is connected on the base stage of amplifier tube 15 through current-limiting resistance 14; interference-free for guaranteeing subscriber phone 16; string has photoelectric coupling circuit 17 and is attempted by shunt resistance 18 on it on telephone wire 1, and the photoelectric tube in the photoelectric coupling circuit 17 is attempted by the collection of transistor 6; on the emitter-base bandgap grading.Its operation principle is: when front end did not have the phone of usurping, resistance 4 and 5 dividing potential drops made transistor 6 conductings, and its current collection is high level very, made transistor 8 and 9 end, and no current passes through on the resistance 10, thereby the feeder ear no signal of signal generating circuit 12 can be supplied.When front end has the words of robber to take place, telephone line has pressure drop, transistor 6 is ended, thereby make very low level of pipe 6 current collections, pipe 8 and pipe 9 conductings, two pipe conductings make its operate as normal through resistance 10 to signal generating circuit 12 power supply, thereby make 12 outputs apply an interfering noise by amplifier tube 15 in telephone wire or jammer signal makes it converse.When rear end private telephone 16 uses, because the photoelectric tube in the photoelectric coupling circuit 17 is in low resistive state when work, makes the base stage of transistor 8 be in high level, thereby make its composite switch circuit be in off state, just can not cause interference effect to in-house machine yet.
Embodiment 1: rectifier diode: IN4004 * 4, resistance 4:1.2M, resistance 5:60M, transistor 6,8 and 9:PNP type, resistance 7:40M, resistance 10:5K, voltage-stabiliser tube 11:10V, signal generating circuit: 2559 (or 5087), crystal oscillator: 3,85M, resistance 14:51K, transistor 15:PNP type 5551, photoelectric coupling circuit 17:620 (or 626), resistance 18:100 ohm.
Claims (3)
1. a telephone line is prevented usurping device, comprises bridge rectifier, bleeder circuit, composite switch circuit, signal generating circuit and amplifier tube and photoelectric coupling circuit, it is characterized by, and bridge rectifier is connected on the telephone line, usurps the device power supply for telephone line is anti-; Two resistance constitute bleeder circuit, dividing point is connected on first transistor base in the composite switch circuit, this emitter just connects, collector electrode connects negative on the one hand through resistance, be connected with second transistor base again in addition, second transistorized emitter is connected with the 3rd transistorized base stage, the 3rd transistorized emitter just connects, second, three transistorized collector electrodes are connected after a resistance inserts signal generating circuit, the signal generating circuit feeder ear connects voltage-stabiliser tube, also be connected with crystal oscillator simultaneously, the signal generating circuit output is connected with the amplifier tube base stage through a current-limiting resistance; Photoelectric coupling circuit be serially connected in the telephone line and and a divider resistance be in parallel, photoelectric tube wherein is attempted by in the composite switch circuit on first transistorized collection, the emitter-base bandgap grading.
2. telephone line according to claim 1 is anti-usurps device, and three transistors that it is characterized by in the described composite switch circuit are positive-negative-positive.
3. telephone line according to claim 1 is anti-usurps device, and it is characterized by described amplifier tube is the NPN type.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95233338 CN2245310Y (en) | 1995-03-11 | 1995-03-11 | Device resisting stealing utilization of electricity for telephone line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95233338 CN2245310Y (en) | 1995-03-11 | 1995-03-11 | Device resisting stealing utilization of electricity for telephone line |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2245310Y true CN2245310Y (en) | 1997-01-15 |
Family
ID=33877499
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95233338 Expired - Fee Related CN2245310Y (en) | 1995-03-11 | 1995-03-11 | Device resisting stealing utilization of electricity for telephone line |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2245310Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1073773C (en) * | 1997-09-19 | 2001-10-24 | 义隆电子股份有限公司 | Device for preventing fraudulent use of telephone subscriber line |
| CN113411009A (en) * | 2021-06-28 | 2021-09-17 | 石河子大学 | Self-powered inductance synchronous switch piezoelectric energy acquisition circuit |
-
1995
- 1995-03-11 CN CN 95233338 patent/CN2245310Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1073773C (en) * | 1997-09-19 | 2001-10-24 | 义隆电子股份有限公司 | Device for preventing fraudulent use of telephone subscriber line |
| CN113411009A (en) * | 2021-06-28 | 2021-09-17 | 石河子大学 | Self-powered inductance synchronous switch piezoelectric energy acquisition circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |