JPS58143659A - Detector for telephone wiretap - Google Patents

Abstract

PURPOSE:To facilitate the attachment of a wiretap detecting circuit and to ensure the interchangeability between a telephone containing a wiretap detector and another telephone containing no wiretap detector, by detecting a telephone wiretap through a wiretap detecting circuit and from the difference of voltage that is applied to a telephone line and then connecting the substrate of the wiretap detecting circuit to the handset connecting part of a telephone. CONSTITUTION:The change of voltage between X and Y of a telephone line is detected by a diode D, a transistors TRQ1-Q3, a light emitting diode LD, etc. This mechanism is formed on a printed circuit board 1 in the form of a wiretap detecting circuit. This board 1 is connected to a transmitter microphone M having transmitter connecting parts 3 and 4 and fixed with the microphone M by a cover screwed from above. The connecting part on the rear side of the microphone m is connected to the bottom surface of the board 1, and connecting surfaces 5 and 6 are formed to the parts 3 and 4 respectively. Thus the board 1 containing a wiretap detecting circuit can be simply attached to the microphone M of a telephone set, and the interchangeability is secured between a telephone containing a wiretap detector and another telephone containing no wiretap detector.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a wiretapping detection device #ICIM1 that can be easily attached to an ordinary telephone.

- When multiple telephones are connected in parallel to the same telephone line, if one of the telephones is busy and you pick up the handset of the other telephone, you will receive 11i% of the charge for that telephone.
-Can be eavesdropped. In this case, the same telephone number, II
K: When the handsets and receivers of all connected telephones are connected, a voltage of approximately 50 volts is applied to both terminals of the telephone, but when only one telephone is used for making and receiving calls*1, this voltage decreases to approximately 50 volts. If you pick up the handsets of two telephones at the same time, the voltage will drop further to about 4.5 volts. Therefore, by detecting the difference in the voltage applied to this telephone IIK, it can be discovered that the telephone is being tapped. However, until now no wiretapping detection device that could be easily attached to a regular telephone had been developed.

The present invention aims to provide a wiretapping detection device V that uses the above-mentioned original @ and can be easily stored in the transmitter housing of an ordinary telephone. Hereinafter, the present invention will be specifically explained with reference to the drawings.

Diagram Ic1 is an internal circuit diagram of an ordinary telephone.

In the figure, L1 and L8 are telephone lines, B is a bell, C is a capacitor, H8 is a 7-way switch, M is a transmitter, R is a receiver, and L is a coil. Further, X and Y indicate the positions where the eavesdropping detector used in the present invention is connected.

82WA is a circuit shown as an example of a wiretapping detector used for a single-wire @. In the figure, X and Y indicate the same positions as X and Y in the all figures, and when you pick up the handset, the
Switch H8 closes and the voltages at telephone 1iLt and R1 are applied to XY. However, when the handset is raised by 1 kMR, the voltage at both ends of the telephone line and therefore the polarity of the voltage between It is a fixed resistor.The semi-fixed resistor VR is adjusted and fixed by Km so that the transistor Q1 is turned on when the voltage between XY is about 6 volts and turned off when the voltage is about 4.5 volts or less.Transistor Qs is turned on. When , transistors Q2 and Qs
is off, so the light emitting diode LD does not light up. E is a small battery, for example a mercury battery.

If the telephone is currently busy, the light emitting diode LD will not light up unless another telephone is eavesdropping, so you can be sure that the telephone is not being eavesdropped.

However, when other Kameti machines are eavesdropping, the XY electrical voltage drops to about 4.5 volts, transistor Ql turns off, transistors Ch and Qs turn on, and the light emitting diode LD lights up. By lighting up the light emitting diode LD, it is possible to detect that eavesdropping is occurring.

When the handset and receiver are connected, the voltage between X and Y becomes constant, transistors Q2 and Qs are turned off, and one light emitting diode LD goes out. However, a single transistor may also be used.

Diagram 3 is a diagram showing the implementation bait of the present invention attached to the transmitter of telephone number 4, which is a wiretapping detector such as the one mentioned above. .

FIG. 3C is a bottom view thereof.

In the figure, (1) is a printed circuit board on which a wiretapping detection circuit as shown in Fig. 2 is formed, but electrical components are omitted in the figure. (2) is a printed circuit board support metal fitting, which is fixed to the lower surface of the case M1 of the transmitter M by, for example, soldering. M2 is a sound hole drilled on the top surface of the transmitter case M1, and the light emitting diode LD is
The upper surface is attached using a hole drilled in the center so that it protrudes from the upper surface. As shown by the dotted line in the ms diagram BK, the transmitter housing of the handset of the No. 4 telephone is equipped with contact pieces (3) and (4) inside as a transmitter connection means, and these contacts +31, (41K Touch the connection S on the back of the transmitter M, store the transmitter Mv, and from the top:
The ll1t screw is enlarged to fix the transmitter Ml.

Therefore, in this embodiment, as shown in Fig. 3 CK, the bottom surface of the printed circuit board (1) is provided with a connection # that connects to the connection portion on the back surface of the transmitter M and contacts the contacts (3) and (4) ε. J(
51 and (6) are provided. 11 Continuous surface (5) is Ii piece (
3), make a hole in the center of the printed circuit board (1).

The hole can be formed so that the center connecting portion of the transmitter M is exposed through the hole. The connecting surface (6) is in contact with the contact piece (4), and is formed by forming an annular conductive layer on the bottom surface of the printed circuit board (11) and connecting it after connecting the other side of the transmitter M. It can be formed by

A circuit button, a bulge, etc. are formed on the outer periphery of the bottom surface of the printed circuit board (1), but they are not shown in the drawings.

Like this #IC1 eavesdropping device & -4 telephone transmitter M
[If you have a device equipped with an XR, you can easily install the wiretapping detector t' on telephone number 4 by replacing it with the transmitter of telephone number 4, which is actually installed.

Figure 4 shows another embodiment of the present invention in which a similar wiretapping detector is attached to the transmitter of a T-600 series telephone, where Figure 4 is a top view and Figure 4B is a top view. Its side view, IE
Figure 4C is its bottom view.

- In FIG. 4, parts corresponding to those in FIG. 3 are indicated with the same reference numeral Kf. In the 600 series telephone set, connection wires (3') and (4') are provided in the inner W in the intercom housing of the handset, as shown by the dotted line in Figure 4B, and these ends are connected to each other. The transmitter connection tap (5 and (69) protruding from the back side of the transmitter d is inserted into the transmitter M' to store the transmitter M'. Also, the transmitter storage section is provided with a stepped section. Therefore, in order to make the installation easier by using this, a plate (7) is provided for the cover and mounting.In this embodiment, as shown in Fig. Drill a hole in the center of the board (7) and make the transmitter connection tap (5) protrude from this hole. The connection wire (4) and the transmitter connection tap (6'l) can be connected through this notch.

In this way, if you attach a wiretapping device to the transmitter M' of a 600 series telephone, you can
The wiretapping detector can be easily attached to the V600 series telephone by replacing the transmitter of the series telephone.

As is clear from the above explanation, the present invention can be used to install wiretapping detectors on currently installed telephones without any modification. Therefore, according to the present invention, the handset of a No. 4 or 60G series telephone is compatible with the handset. There is an advantage in that the wiretapping detector can be easily attached to the telephone, rather than having to install the wiretapping detector according to the present invention, that is, the telephone transmitter with the wiretapping detector, and tighten the fl.

Note that the present invention is not limited to the above-mentioned embodiments, as long as it falls within the gist of the invention described in the claims.

For example, 0 is subject to various modifications and changes.

The light emitting diode LD can also be installed in a place where it cannot be seen from the outside.

[Brief explanation of drawings]

FIG. 1 is an internal circuit diagram of an ordinary telephone, and FIG. 812 is a circuit diagram showing one example of a wiretapping detector used in the present invention. FIG. 113 is a diagram showing the first embodiment of the present invention, and FIG. 4 is a diagram showing the second embodiment of the present invention. (1)...Printed circuit board, M, M'...
- Transmitter, (3, 4), (3', 4')...Transmitter connection part. Figure 1 Figure 2 Figure 3 Figure 4 [Procedural amendment April 2, 1939, Haruki Shima, Commissioner of the Japan Patent Office (Chief Examiner of the Japan Patent Office 1, Indication of the case, Showa S7, Patent Application No. 11!1497) 2. Title of the invention Telephone eavesdropping device 3. Relationship with the case of the person making the amendment Patent applicant: Tokyo (03) 343-5821 (representative) 6. If the number of inventions increases due to the amendment, XY@voltage There are more than hooks and porto,” he says firmly.

Claims (1)

[Claims] A printed circuit board with a wiretapping detection circuit formed thereon is fixed to the back side of a transmitter of the same structure as that used in telephones, and this printed circuit board is used to connect the transmitter and the telephone Kf & cut transmitter connection part. A telephone eavesdropping detection device configured to connect and connect without any additional means.