Advertising on the portal

Scheme for recording telephone conversations of a landline phone. Recording telephone conversations on a computer

Ootosis of the Soviet

Socialist

Republics

Auto dependent. certificate No. —

M. Cl. H 04m 1.64

Applied on 22L11.1971 (No. 1638238/26-9) with attachment of application “¹â€”

Ori Sovete Miiistroe

UDC 621.395.348.5 (088.8) V. L. Kotlyarov and Yu. B. Mandel

Lviv Order of Lenin Polytechnic Institute

Applicant

PHONE CONNECTOR

TO DICTOPHONES

The invention relates to the field of telecommunications.

A device for connecting telephones to voice recorders is known, containing a relay, a stepper finder and a pulse generator. To connect to the voice recorder, the subscriber needs to dial the voice recorder's number using a dialer, and if the voice recorder is busy, it must be dialed again.

The purpose of the invention is to reduce connection time.

To do this, the input of the pulse generator is connected to the inputs of telephone lines through a series-connected reference diode and an "OR" circuit. One of the ends of the relay winding is connected through a thyristor to the contacts of the stepper finder, and an additional reference diode is connected between the anode and the control electrode of the thyristor.

The drawing shows a diagram of the device.

The device contains an "OR" circuit 1, a stepper finder 2, a reference diode 8, a pulse generator 4, a thyristor 5, a relay b, an additional reference diode 7.

Terminals 8 are connected to telephone line inputs. The inputs of all telephone lines are also connected to the lamellas 9 of the contact field of the stepper finder 2. The output of the generator 4 through n. h. contact 10 is connected to the winding of the stepper finder 2, and through n. about. contact 11 - with the next similar recorder control unit.

When called, a line voltage occurs at terminals 9 connected to the calling line, which, through circuit 1 and diode 3, enters generator 4 and turns it on. The generator pulses through contact ll enter the winding of the stepper finder 2. The finder brushes move and stop at

10 lamellas with linear voltage. The reference diode 7 opens, the relay b is activated and the generator 4 is turned off, and when the next step finder is working, the parallel connection of two voice recorders to

15 to one telephone channel. With its contacts, relay b switches the voice recorder control unit. The sound voltage and the voice recorder turn-on voltage are removed from the relay winding. The relay is switched off on reset.

Subject of invention

A device for connecting telephones to voice recorders, containing a step finder, the contacts of which are connected to the inputs of telephone lines, a relay, a pulse generator, the output of which is through n. h. the relay contact is connected to the winding of the stepper finder, which differs in that, in order to reduce the time 363223

Compiled by M. Porfirova

Redvk, OR L Mazurovka Tekhred T. Uskova, Proofreaders L. Tsarkova and E. Mironova

Order 993 Ed. No. 58 Circulation 404 Subscription

TsNIIPI of the Committee for Inventions and Discoveries under the Council of Ministers of the USSR

Moscow, 5K-35, Raushskaya emb., 4!5

Printing house ¹ 224 4 CSoOIyuoz3p ool ​​iNg r9a f pnr9oomMa, Moscow skKvVa, G-19, st. Marx-Engels, 14 connection menu, the input of the pulse generator through a series-connected reference diode and the "OR" circuit is connected to the inputs of telephone lines, and one of the ends of the relay winding through the dash and the stor is connected to the contacts of the stepper finder, and between the anode and the control electrode of the thyristor an additional reference diode is connected.

Similar patents:

The invention relates to telephone communications, and in particular to devices for matching a telephone line with a capacitive load when the latter is connected to the line through a diode decoupling, and can be used, for example, in a telephone line voltage rectifier, in diode splitter attachments of a paired line

This article discusses the issue of choosing a system for recording telephone conversations. The criteria that should be taken into account when choosing the optimal system are analyzed and examples of devices are given. Various models are described with saving conversations to a computer and offline with recording to an SD card, recommendations are given for their use.

Why do we need a system for recording telephone conversations on a computer?

Call recording systems are widely used in the corporate world. Using these systems and listening to employees' calls makes it possible to improve the quality of work of the company's personnel and, thanks to this, increase customer satisfaction with the quality of service. The very fact of control disciplines employees. Recording telephone conversations on a computer serves the following purposes:

  • Increasing the level of security by recording all conversations;
  • Mandatory registration of conversations in security, dispatching and emergency services;
  • Training employees on successful examples of sales and communication with customers;
  • Improving the quality of personnel work by monitoring their activities;
  • Reducing the cost of long-distance calls;
  • Resolution of conflict situations with clients;
  • Recording of telephone conferences;
  • Reducing data leakage.

Due to the advantages described above, use of recording systems telephone conversations guarantees increased efficiency company work.

Criteria for selecting a call recording system

When choosing a system, you need to pay attention to how convenient it is implemented. The functions of such equipment are usually quite standard. Therefore, the selection of a telephone conversation recording system for your company should be carried out based on the technical capabilities of the equipment. In order to make the optimal choice, it is first necessary to designatea list of the main parameters that the planned system should provide. The implemented equipment is an addition to telephony, designed to automatically record telephone conversations and save them as files, and should not make any changes to the operation of the PBX or telephone sets. The equipment must work simultaneously on several telephone channels to record incoming andoutgoing calls. If necessary, access to the database of recorded files should be provided at any time, and their playback - with good quality. Based on this, we list the selection criteria:

  1. Reliability of the devices used;
  2. Possibility of registration tax or digital channels;
  3. Work together with a computer or autonomy;
  4. Number of recorded channels;
  5. The presence of a convenient interface for working with recorded files;
  6. Possibility of access to the archive of calls over the network;
  7. Power supply: external or from line/computer;
  8. The presence of a warning about the recording;
  9. Definition of incoming and outgoing numbers;
  10. Device case form factor;
  11. Ability to integrate with third-party software;
  12. Additional features.
1) Reliability.

An important parameter, since if the reliability of the equipment for recording and storing sound files is not ensured, then all the advantages listed above will come to naught. If the system does not provide flawless operation in 365 days/24 hours mode, then it may turn out that the most important conversation was not saved. You can, for example, use a Chinese phone with the function of recording conversations with the android program. But this is only suitable for private non-commercial use due to its inability to work stably in intensive use. The use of domestic specialized SpRecord or ICON devices guarantees high reliability of work.

2) Recording system for analogue or digital channels.With this criterion, everything is extremely simple, the type of system is selected in accordance with the telephone channels used in your organization: analog or digital. It is possible that your hybrid PBX works with both analog and digital lines. In this case, it is necessary to provide an appropriate number of registrars of each type.

Analog phone call recorder SpRecord A1:

Digital call recording system SpRecord ISDN E1:

3) Autonomy. If the device works in conjunction with a computer, then the archive of conversations is kept on the hard disk of the PC, the amount of available space on which determines the recording time. In standalone operation, saving goes to an SD memory card, and the recording time depends on the capacity of the card and the degree of compression of the recorded file.

Autonomous system for recording telephone conversations ICON TR1(18 hours of continuous recording on 1 Gb of memory):

4) Number of channelsregistration systems. This choice depends on the terms of reference: if it is enough to record only conversations with clients, then the number of channels should be equal to the number of external lines of the mini-PBX. If it is necessary to register all conversations, including those within the organization, then - the number of internal lines of the office PBX.

4 channel analog system SpRecord A4:

5) The presence of a user-friendly interface to work with recorded files. This function is important in order to be able to quickly find and play the desired sound file. This requires a clear user interface and convenient search by various criteria: date, time, subscriber number, outgoing number prefix, etc. This also includes the ability to maintain a database on Microsoft SQL Server with the ability to work with the archive of calls using Microsoft tools.

6) Ability to access the archive of calls over the network. This criterion, in fact, follows from the previous one. For the convenience of working with the database of calls, access to the archive must be provided remotely, via the network. To listen to the recordings, both the manager and the system administrator and other persons who were allowed access to this information by the management could. In addition, in this case, the rights of users should also be distinguished to exclude the possibility of accidental or intentional deletion of records.

7) Nutritiondevices from the port Computer USB or communication lines are more convenient in that a network adapter and an additional 220 V socket are not required. However, they may not work on channels with low line voltage, for example, if there are several parallel telephones, or on Kvant PABX lines, In these cases externally powered devices are required.

Call recording system SpRecord AU1DC powered by 220V / 5V adapter:

11) Ability to integrate with third-partyON. Recording system developers can provide SDK (software development kit) - a set of development tools - for embedding in third-party software. This allows the call recording program to be integrated into your existing telecommunications software in such a way that it becomes an integral part of it and as convenient as possible for work. The SDK is provided, for example, by SpRecord.

12) Additional system features. It can be, for example, autoinformer, autoresponder, autoattendant, autocall. The answering machine announces the upcoming recording of a telephone conversation or can play a pre-recorded audio file, the answering machine can record a voice message for a subscriber who, in this moment cannot answer the call. The auto attendant allows you to redial the subscriber's internal number, and the auto redial makes automatic calls and the issuance of a recorded message.

Call recording device with autoinformer Icon TRX1AN:

Choosing a manufacturer of equipment for recording telephone conversations

Currently, the market for call recording systems offers equipment from several manufacturers, which can be divided into two groups based on cost:

  • Systems Octopus, Forget-Me-Not, Phantom.
  • Devices SpRecord, ICON.

Systems from the first group have a fairly high cost and are used mainly in large companies and special services. R consider system manufacturerscall recordings for small and medium businesses.

SpRecord- brand of the company LLC "Sarapulse systems". Products of this brand are easy and simple to connect and easy to use. The equipment is produced for analog and digital lines. Basically, the devices work in conjunction with a computer and record to a PC hard drive, but there are also stand-alone models, as well as models with an answering machine, support for an auto attendant and auto-dialing.

ICON- brand of scientific and production company "IKON". Its products are manufactured on the basis of the latest element base from the best manufacturers electronic components such as Analog Devices, Atmel, Microchip, Samsung, TI. Products are of high build quality and reliability, besides, they are the most affordable.

Systems for recording telephone conversations SpRecord

The manufacturer of SpRecord brand devices is Sarapul Systems LLC from Udmurtia. SpRecord products can work with analog or digital channels. Features of SpRecord adapters are ease of connection and configuration, as well as low price. Any Sp Record device comes with a CD containing a program for recording telephone conversations.SpRecord devices have the most favorable price for the user, based on the cost of equipment per one recorded line.

Sarapul Systems products can work not only with analog or digital lines, but even connect directly to the handset of a telephone set . For example, telephone registrar SpRecord TT records conversations directly from the handsetany telephone, including analog, system, hybrid, VoIP phone:

Below is a table designed to help you choose the optimal SpRecord model.

ICON call recorders

The manufacturer of ICON devices and the owner of the brand is the research and production company "ICON" from St. Petersburg. NPF ICON has long been engaged in the development and production of equipment for telephone communications. The equipment is produced on the basis of the latest element base from the world's best manufacturers of microelectronic components. Among the products: systems for recording telephone conversations, auto attendants, autoinformers, callback detectors, current boosters. Features of ICON equipment are autonomy, ease of connection and low price. At ICON devices save conversations to an SD memory card, but there are new models with computer recording. Available in line-powered and AC adapter-powered versions.

2-channel adapter-powered call recorder Icon TRX2:

For the convenience of choosing the most optimal ICON call recording device for your conditions, the corresponding table is given below.

Recommendations for the selection and use of telephone conversation recording systems

SpRecord and ICON call recording devices have similar specifications and are in the same price range. How to choose the right manufacturer and model?

If you t requires an offline recording system, we recommend choosing a device from the ICON line . Models of this brand are also convenient ifit is planned to attach them to walls e.

To record conversations on a computer, we recommend using SpRecord devices. If you need to have an answering machine, auto attendant or auto-dialing, you can purchase models of the appropriate type. In addition, the manufacturer offers an SDK package for integrating its software into your existing communication software.

It is well known that a lot of programs for recording telephone conversations have been written for all mobile platforms. These are such well-known programs as rVoix, AudioSP, Auto-call, PsilocXelnex - you can do them. But what if you need to record a conversation on a regular landline phone or a wired voice source? This is where this simple device comes to the rescue, which does not require scarce parts or a lot of experience for its manufacture.

In TV shows, you can often see how the problem of recording telephone conversations is solved with the help of a camera and a hands-free phone. Naturally, the recording quality and intelligibility in this case leave much to be desired. Once I happened to see a special voice recorder with RJ11 connectors for recording telephone conversations at a prosecutor. And so the idea of ​​creating a telephone line adapter for a conventional voice recorder appeared.

Device diagram

Scheme of an adapter to a telephone line for recording conversations before and after rework

I took the old D-LINK splitter DSL-30CF as a basis. It turned out to be exactly the same circuit as most cheap splitters. On the Internet, I managed to find a Zyxel splitter circuit, exactly like mine. The diagram shows that the connectors: LINE and ADSL are connected directly to each other, and the PHONE connector is connected through an RF filter. From the circuit, I dropped both transformers, and all four capacitors (They will come in handy for me to make a "spy" fitter's tube). I left only sockets and a varistor (let there be protection for the phone from surges and ears from loud clicks). I soldered wire jumpers into the circuit so that I could get a telephone splitter (by the way, you can use this device that way). AT top cover The splitter made two holes for the headphone jacks, so that they fit snugly there and fit into the space between the telephone sockets freed up after the removal of the high-frequency filters.

In the circuit I used electrolytic capacitors rated for 50V. You can take it with a lot of pressure. You can also exclude one of the headphone jacks from the circuit. I put two, so that you can control the recording process.

As a voice recorder, I used an old RoverMedia MP3 player, model: Aria DP300FM, since it has a line input for recording in one of the selected formats and is equipped with a special connecting cord, which I used. In addition, this player has an excellent function to record only when there is a signal. Of course, you can also record to a regular voice recorder or computer through the line-in. He happens of blue color. Or if it is missing through the microphone (it happens to be red). In any case, before recording, you should adjust the signal level.

If there is no adapter cord, one can easily be made from a pair of old headphones by simply connecting the appropriate leads together.

The principle of operation of the device is very simple. As you know, telephony uses several components of the operating voltage. When the handset is hung up in the telephone set, a ringing circuit is connected to the line, through a capacitor of about one microfarad. DC current does not flow through this line, but when a call signal is applied to the phone, more than 100 volts and about 25 Hz, the capacitor recharges and current flows through the ringer. When the handset is picked up, the conversational and dialing circuits are connected to the line, creating resistance in the line direct current.

This is how the station determines whether the machine is ready for dialing or connecting. Since the adapter does not create resistance to direct current, it does not interfere with pulse dialing, and does not occupy the line, which means it can be on the line all the time. As you can see from the adapter diagram, when the voice recorder or headphones are turned off, it does not affect the telephone line at all (except for varistor protection).

You can connect the adapter using a 15 cm cord, which is usually supplied with ADSL modems. You can also make it yourself using a crimper, from a piece of telephone cable. It should be borne in mind that analog telephony uses two middle RJ11 outputs (usually red and green).

Using such a cord, you can connect the phone through an adapter, or plug the adapter into any parallel telephone socket (only after the splitter, otherwise the adapter capacitors will bypass ADSL through the input circuits of the recorder). I plugged the adapter into an additional socket on the phone itself, it is usually connected in parallel with the main one.

The adapter is now permanently included in our phone, as it turned out that it is very convenient to participate in a telephone conversation through the connected headphones. In addition, you can connect computer speakers instead of or together with the recorder. Thank you all for your attention. The article was prepared by Zilord.

In general, the topic itself is not new, but browsing amateur and professional sites dedicated to communication technology has shown that interest in this topic is not waning. Such gadgets are produced by separate commercial offices, but for some reason their products are distributed mainly through online stores, and the prices are quite high. Adapters are sold with digital voice recorders for recording telephone conversations, but they become useless if you are the “happy” owner of a paired number - telephone polling pulses are not filtered by the standard adapter and are perceived by the microphone input of the voice recorder. As a result, the function of activating the recording by a sound signal does not work - the recorder is always on, regardless of whether the handset is picked up from the device or laid down. Meanwhile, it is not at all difficult to make a high-quality adapter that takes into account the realities of the domestic telephone network. The adapter will help to record the necessary call with important information on a voice recorder (tape recorder, computer).

I tried to "fix" various circuit solutions that I came across on the Internet and in the literature. Figure 1 shows a conditional classification of adapters by type and, accordingly, by application with various recording devices:

The most convenient, of course, is a parallel connection to a telephone line. However, such an implementation imposes certain technical requirements to the circuit and its elements - the adapter is the load of the PBX line. Figure 2.1 shows the possible connection points for the adapter in parallel with the PBX line.
Inclusion of the adapter into the gap of one of the line wires, of course, simplifies the circuit design, but then the telephone line will have to be broken, and the place of the break must be “calculated” depending on which section of the line it is necessary to control the telephone sets. Such adapters are more suitable for working with an individual phone and are usually located near it. Figure 2.2 shows examples of connecting a line wire to a break. To make a record from all telephones, the line wire is broken at the beginning of the telephone wiring. In the figure, this is a special socket for the adapter, and the adapter must be constantly connected to it. If the adapter is disconnected, then a plug with a jumper is inserted into the socket instead, otherwise the telephone connection stops working in the entire room.
Adapters without galvanic isolation from the telephone line are used with battery-powered recorders and (or) receiving external power from a conventional transformer source with a stabilizer.
For recorders powered by pulse source(e.g. computers, digital voice recorders with battery charging via USB), galvanically isolated adapters are required. This will firstly provide safe operation the device itself, and secondly, it will not affect the telephone line in terms of "ground leakage". As you know, the positive pole of the central battery at the telephone exchange is always grounded.
Non-power-management adapters are easy to connect to the recorder - communication is only through an audio cable. As they say, "Plug and Play" - plug and play. But, with such adapters, only voice recorders can work for a long time. Only voice recorders have a voice activation function (beep). The use of conventional cassette recorders for long work, with a standby mode, will not work, they do not have a voice control function in recording mode. Therefore, tape recorders with such an adapter can only be used for local recording - turning on at the beginning of a conversation and turning off at the end.
Another thing is the adapters that control the power of the recording device. When you pick up the handset from the unit, the device is in recording mode, power is supplied and it is activated. Standby mode can continue indefinitely while on-hook, with the battery or AC power completely turned off. Here, by the way, the problem of the operation of the recording device on the paired PBX line is automatically solved.
Using the telephone line power adapter to operate is classic version regardless of other types of circuit design. Here both transformer binding to the line and capacitor can be used. But these are the simplest solutions. To expand the functionality of the adapter will allow additional power, which is convenient to use as an external power source for the recording device.
By implementing the types listed above in the necessary combinations, it is possible to manufacture an adapter circuit that fully meets a specific application.
On sale there are unbreakable sets RTSHK - telephone socket with a plug or different kind adapters that allow you to connect imported phones with a Jack RJ-11 plug to a domestic socket. Such kits or adapters are very convenient to use as an adapter case:

An example of the simplest adapters included in the break of any linear wire is shown in Figure 3:

A test and breadboard version of these adapters is shown in the photo:

In the circuit in Figure 3.1, a diode bridge VD1 is included in the break of the linear wire, the load of which is a fritter built on two germanium diodes connected in anti-parallel. The voltage drop across VD2 and VD3 is no more than 200…300mV both for an incoming call and when the line is busy. A capacitor C2 is connected to the fritter, which produces an alternating conversational current. For alternating current capacitors C2 and C3 are a capacitive divider and form a kind of filter. From capacitor C3, an alternating signal from the line is fed to the microphone input of the cassette recorder. Capacitor C1 additionally shunts the input circuit of the adapter. It eliminates noise on the telephone line when the handset is on-hook and reduces the effect of AC calling voltage. The operating voltage of the capacitor must be at least as indicated in the diagram. In this circuit, you can install a line occupation indicator if, instead of VD2 and VD3, you turn on the LED with the anode to the plus of VD1. The constant voltage will then be limited to the level of the voltage drop of the type of LED used.
In the circuit in Figure 3.2, two silicon diodes VD1 and VD2 and the primary winding of the transformer T1 are included in the break of the linear wire. The voltage drop across the diodes does not exceed 600 ... 700mV both during an incoming call and when dialing a number, therefore, the diodes limit the voltage amplitude of the primary winding T1 at a safe level. From the secondary winding T1, the signal is fed to the tuning resistor R1, with the slider of which you can set the required level of the variable signal at the microphone input of the recorder. Capacitor C2 is separating. It is necessary if the microphone input of the recorder in the recording mode is "on duty" with a constant voltage (usually 0.9 ... 1.5V), which is used to power the connected external electret microphone. Capacitor C1 additionally eliminates interference. Any transformer T1 can be used, as small as possible, with a transformation ratio Ktr = 1 ... 10 and is selected experimentally according to the nominal level of the recorded signal.
Another version of the circuit design of the adapter included in the line wire break is shown in Figure 4. Here, the adapter uses a relay:

Figure 4.1 shows the diagram of the adapter that controls the voice recorder's power supply. In the initial state, when the handset is laid down, a voltage is applied to the VD1 diode bridge, determined by the current that the telephone set consumes from the PBX line in the last dialed number storage mode, if it is an electronic SLT with push-button dialing. No voltage is applied to the VD1 bridge if it is a classic rotary dialer SLT. The adapter is connected in series with the TA bell circuit. When an incoming call is received - an alternating voltage with an amplitude of 90 ... 120V, the phone starts ringing, while the ringing voltage is rectified by the VD1 bridge. Through the LED HL1, windings K1 and K2, the circuit closes to minus VD1. The HL1 LED indicates the presence of a ringing signal on the line. But, the phone's calling circuit current, sufficient to ignite HL1, is not enough to create a voltage drop across the resistance of the relay windings so that they work. Therefore, the relays remain in their original state, their contacts K1.1 and K2.1 do not switch, and as a result, the recorder is not activated. When the handset is removed from the device, the line is busy and a current begins to flow through the adapter, sufficient to ignite HL1 and operate the relay. Contacts K1.1 switch, closing the power supply circuit of the recorder, and contacts K2.1 connect the decoupling C3 to the plus VD1. The voice recorder records the conversation. When the handset returns to the device, the circuit assumes its initial state - the voice recorder is powered by the open contacts K1.1, and the decoupling C3 is closed to a common wire by contacts K2.1, i.e. recording stops. Capacitor C1 is storage and gives off its energy when the number is dialed, ensuring that the relay is kept on. Without it, the relays will switch with the dialing frequency (standard F=10Hz). The HL1 LED, in addition to the function of the indicator of an incoming call and the occupation of the line, blocks the shunting effect of the capacitor C1 on the alternating conversational current. Capacitor C2 - anti-interference. Diodes VD2 and VD3 eliminate negative self-induction voltage surges that occur when the relay is released. Recommendations for the use of the relay are given in the diagram, while we must not forget that the winding resistances K1 and K2 are connected in series with the conversational TA circuit and work as an additional resistance when dialing a number. Therefore, the lower their resistance, the better. According to this scheme, a working copy of the adapter was assembled, which fit in a socket with two RJ-11 connectors:

Contacts K1.1 operating in the power supply circuit of the recorder can be connected as follows. An insert is made of a thin but solid non-conductive material, which is placed between the battery and the contact in the voice recorder case. If this insert is used for one battery, then it is made according to the size of the battery diameter and has two contacts on different sides:

If this is an insert for two batteries, then it can be made rectangular:

In both cases, in the battery cover for the wire going from the insert to the adapter, it is necessary to make a small neat cut with a needle file. Then it will turn out quite aesthetically:

In order not to pull the wire out of the battery compartment every time you listen to a recorded fragment, the adapter has a SA1 switch (see Figure 4.1). Closed contacts SA1.1 are included in the audio circuit, and open contacts SA1.2 are included in the power circuit. Before listening to the recording, SA1 is switched, then the power circuit is closed, and the audio signal circuit, on the contrary, is opened. Now you can control the voice recorder using its standard buttons, and the sound signal will not be sent to the microphone input if it becomes necessary to have a telephone conversation.
This adapter can not only control the power of the voice recorder:

But, also be used without power management, ie. in beep activation mode:

Figure 4.2 shows a simplified version of such an adapter - without voice recorder power management. Both schemes are ideal for working on a paired PBX line.
Examples of adapters connected in parallel to a telephone line are shown in Figure 5:

The adapter controlling the voice recorder's external power supply is shown in Figure 5.1. Here, an SA1 switch is installed at the input, connecting the adapter to ATC1 or to ATC2. The diode bridge VD1 ensures the constancy of the polarity of the supply voltage in the circuit and rectifies the alternating voltage of the call. Divider R1-R2 and transistor VT1 - line status sensor “busy; not busy; dialing a number". Elements R3 and C1 are the delay circuit, and VT2 is the current switch that controls the power of the recorder. As can be seen from the diagram, the switching of the voice recorder supply voltage is carried out "by minus". In the initial state, with the tube laid, the line is not busy and there is a voltage of the order of 2.0 ... 2.3V at the VT1 gate. The transistor is open and the voltage potential on the positive plate of the capacitor C1 is practically zero, i.e. C1 is discharged, and the transistor VT2 is closed. The circuit "minus source GB1-GB2" - "minus external power supply" of the recorder is broken. The current consumption from the line by the adapter circuit in this case is determined by the parallel connection of the resistances (R1 + R2) and R3, i.e. no more than 40 µA. When the tube is removed, the voltage at the gate VT1 becomes less than Uz-and the threshold and the transistor closes. C1 starts charging through R3 and, when the voltage on it exceeds the Uz threshold, the transistor VT2 opens, closing the negative wire of the external power supply of the recorder with the minus of the source GB1-GB2. The recorder turns on and records the audio signal from the line, emitted by the capacitor C2 through R4. Capacitor C3 eliminates noise and interference. The voltage on the capacitor C1 will increase until it becomes equal to the voltage in the busy line (as a rule, U = 8 ... 15V and is determined by the subscriber device), therefore, it will not exceed Uz-and max VT2. The diagram shows the voltages measured when removing the tube from the push-button SLT of the GE brand, taking into account the input resistance of the digital multimeter. When dialing a number, pulses with an amplitude of up to 60V appear on the line. At the VT1 gate, the voltage will reach Uz-and threshold and it will open again, instantly discharging C1. Transistor VT2 will close, de-energizing the recorder. During the repetition of serial pulses and in the pauses between them, C1 will not have time to charge, periodically discharging through a low resistance (Rc-and open = no more than 10 Om) of the drain-source transition VT1, so VT2 will remain closed and the recorder turned off. After dialing the entire number, C1 will charge and the recorder will continue recording. With an incoming call, the picture is similar to the dialing mode, so the voice recorder also remains off. The table shows the instances of transistors that were tried as VT2, as well as the measured voltage drop (+ Upad *) at the open drain-source junction with "fresh" batteries GB1 and GB2. The use of IRFZ44N turned out to be more preferable - the voltage drop was no more than Upad = 4.0 mV.
The adapter according to this scheme was assembled in an arbacom socket with RJ-11 connectors due to its increased size, which made it possible to place a case for two AAA batteries, having previously cut a hole in the bottom to size:

The diagram in Figure 5.2 shows a non-power-managed adapter with the audio output closed in standby mode. The node on transistors VT1 and VT2 works in the same way as in the circuit in Figure 5.1, while the voltage U \u003d 60V of the idle PBX line from the bridge VD1 through R4 goes to the zener diode VD4 and is limited at the level Ustab \u003d 8 ... 10V. Capacitor C2 smooths out the ripples. The voltage from the cathode VD4 is supplied to the gate VT3 and opens it. With its open drain-source junction, the transistor connects the left side of capacitor C3 to a common wire. As a result, a capacitor with a capacitance C = 330nF + 1mF is connected in parallel with the microphone input of the recorder, which cuts off interference and shunts the alternating voltage of the incoming call, which, thanks to the divider R5 and Rc-and open VT3, is reduced to the noise level. The current consumption of the adapter is determined by the parallel connection of resistors R1 + R2, R3, R5 and the current flowing through R4 and VD4. When the tube is removed from the device, the transistor VT2 opens and discharges C2, while the gate VT3 closes to a common wire. Transistor VT3 closes and an alternating signal through R5 and C3 is fed to the microphone input of the recorder. When dialing a number, transistor VT2 will quickly close, but due to the large value of R4, capacitor C2 will not charge immediately, so VT3 will remain closed for some time. To prevent pulses with an amplitude of up to U = 60V from passing to the microphone input, a protective silicon diode VD2 is installed, which limits the voltage at a level of no more than 600 ... 700mV. In this case, R5 limits the current through the diode. Despite the large values ​​of R5 and C4, the level at the microphone input is sufficient for normal functioning beep recording activation mode. You can increase the signal level by adding diodes in series with VD2.
Figure 5.3 shows the adapter circuit with galvanic isolation. The HL1 LED is included in the drain circuit of the transistor VT2, which is an indicator of line occupation. When the tube is removed from the SLT, resistor R4 eliminates the shunting of the line by the adapter and limits the current through the LED. The voltage drop on the LED (of the order of 1.5 ... 2.0 ... 3.0V and is determined by the type) is used to remove the signal from the line. Alternating conversational current through C2 is supplied to the winding 1-2 of the transformer T1. From the winding 3-4, the signal through the separating C3 is fed to the microphone input of the recorder. Capacitor C4 is anti-interference and reduces the amplitude of the induced voltage during an incoming call in winding 3-4 at the microphone input to a level at which the voice recording activation system does not recognize the signal. Such pickup occurs despite the fact that the transistor VT2 is closed and the cathode HL1, together with the output 2T1, is disconnected from the common wire of the circuit. The type of transformer T1 is not known and it is not clear whether it is unified or not. I found some at work and it is not clear what they are for or in what device they are used. They have small dimensions. The measured winding resistances are shown in the diagram, although they are not critical - the recorder has a deep ARUZ in the recording mode.
Based on the circuit in Figure 5.3, a two-line adapter circuit has been developed. I use this adapter at my work. The fact is that I have two phones connected at my workplace. One is a regular PBX with a serial number, and the second is a direct connection with the head of the department, i.e. the phone works with the operational communication switch. Previously, when telephone operatives or meetings were held, you had to press the receiver with your shoulder to your ear and manage to write down all sorts of control centers of bosses or technical managers. Tired, so this adapter was made. Now I calmly talk on the phone, and all the information is automatically recorded on the recorder.
Diagrams of two-line adapters connected in parallel with the telephone line and controlling the external power supply of the voice recorder are shown in Figure 6. Figure 6.1 shows a diagram of a two-line adapter with an additional option, and Figure 6.2 shows a simplified version:

As you can see from Figure 6.1, the adapter has two channels of telephone interfaces made according to the same schemes. The channels are interconnected only by the secondary windings of the transformers T1 and T2. This achieves galvanic isolation between telephone lines. The signal in the channels is taken through separating capacitors C3 and C4 from the LEDs HL1 and HL2, which simultaneously act as indicators of the occupation of telephone lines. In addition, emitting LEDs of transistor optocouplers VQ1.1 and VQ1.2 are installed in the drain circuit of transistors VT3 and VT4. transmitting a signal to the external power control node. Resistors R7 and R8 limit current and eliminate off-hook phone line shunting. The DD1 chip operates in the power management node - four logical elements with the "AND" function and a hysteresis switching characteristic. As an additional option of a voice marker that marks the time of completion (or start and end) of the fragment recording, a talking clock "TALKING CLOCK" has been added to the node.
The work of both telephone channels is the same, so I will consider the work of only one, for example, the first one. When the tube is laid, the transistor VT3 is closed, so the current does not flow through the LEDs VQ1.1 and HL1. Resistor R14 sets log.1-tsu at the inputs 1,2DD1.1, therefore, log.0 is present at the output 3DD1.1 . Log.1 from the output 10DD1.3 through the integrating circuit R17-C13 enters the input 6DD1.4. The input 5DD1.4 is also log.1, so the output 4DD1.4 is log.0. This log.0 closes the transistor VT7. Transistor VT6 is securely locked with a positive potential on the base with resistor R12, so the supply voltage from the source GB1-GB3 is not supplied to the recorder. Log.1-tsey output 11DD1.2 closed transistor VT5 and LED HL3 off.
The incoming call does not trigger any processes in the power management node, so the recorder remains turned off.
When you remove the handset from the device, the line is engaged. VT3 opens and current begins to flow through VQ1.1 and HL1. The HL1 LED indicates the occupation of the line, and the phototransistor VQ1.3 opens in the optocoupler. At the inputs 1.2 DD1.1, the voltage drops to the level of log.0-la. Now, at the inputs 8 and 9 of the DD1.3 element, there are two log.1s, and at its output 10DD1.3, respectively, log.0. This log.0 quickly discharges C12 thanks to the VD5 diode and also quickly discharges C13 thanks to the VD6 diode. From the 4DD1.4 output, log.1 opens VT7, which, through the limiting current R13, connects the VT6 base to the common wire of the circuit. Transistor VT6 opens and power source GB1-GB3 through the emitter-collector junction VT6 and diode VD3 is supplied to the recorder. The recorder, previously included in the recording mode, starts recording the signal from the secondary winding T1. The signal from T1 is fed to the microphone input through the separator C5.
When laying the tube on the device, the phototransistor VQ1.3 closes and a log.0 appears at the output 3DD1.1 with a short delay, determined by the elements R14 and C10. Element DD1.3 inverts this log.0 and log.1 appears at the output 10DD1.3, coming through the discharged C12 to the "TALK" clock input. This is equivalent to pressing the standard clock button of the same name. The clock reports the time, and a PWM signal appears at the outputs out1 and out2 with the amplitude of the clock power supply, i.e. U=3V. At the same time, log.1 from the output 10DD1.3 through R17 will start charging C13, so log.1 at the output 4DD1.4 will be held for some time, sufficient to start the clock and the recorder will not turn off even for a short time. Further, after charging C13, the on state of the recorder keeps the PWM signal from the output out1 of the clock, constantly recharging C11 through VD4 and R15. A voltage with a log.0 level from the output 11DD1.2 through R10 opens VT5 and the HL3 LED indicates the process of recording a time message to the recorder. The PWM signal to the recorder comes through R11 and C9. After the time message is over, log.0 will appear at the 4DD1.4 output, closing VT7 and VT6, and the recorder will be powered off.
If you pick up the handset not to answer an incoming call, but to call yourself and start dialing, then the dialing pulses in the line will close VT3, therefore, the power management circuit will work out as when laying the handset. Therefore, the clock will also tell the time and the recorder will record a voice marker. Thus, when you answer an incoming call, the time message will be recorded at the end of the conversation, and when you dial out, the time message will be recorded both at the beginning of the conversation and at the end.
The dictaphone circuit was placed in a case from a used musical apartment bell "Door bell" with battery power and corridor lighting:

At the watch, “holders” for the strap were ground off with a needle file, and a hole for the watch was cut in the bell case. After that, the clock was glued with glue "second":

Inside the case, two telephone jacks were placed and a board was cut to size:

In Figure 6.1, a fragment of the circuit is highlighted in blue. This is a PWM signal amplifier for the BF1 dynamic capsule. When the build was nearing completion, the amplifier was added to the circuit. The measured resistance of BF1 is R = 140 Om (a telephone capsule from a dead cell is used), so the sound is not loud. Let him purr. Capacitor C8 allows you to record a voice marker if the adapter is used with a voice recorder without power management. If there is no need to record a voice marker, then C8 can be omitted. Diode VD3 reduces the supply voltage to the recommended U=3.6V. At the collector-emitter junction of the VT6 transistor with this model of the recorder and “fresh” batteries, no more than U = 0.33V drops.
In the circuit in Figure 6.2, phototransistors VQ1.3 and VQ1.4 are included in the gate circuit of the KP505A transistor switch. When the phototransistors are closed, the zero potential on the gate sets the resistor R=560K. Power switching in the circuit is carried out "by minus".
The topic is invited to watch demos. Trial calls were made to the telephone informant of the city cinema. The first video shows a recording of the conversation on a voice recorder, and the second - on a laptop. For testing, a simple program for recording from a microphone input was downloaded from the Internet. Naturally, there are more "advanced" programs, for example, automatically start recording when there is a signal at the input of the sound card.

RECORDING A TELEPHONE CONVERSATION ON A DICTOPHONE

RECORDING A TELEPHONE CONVERSATION ON A LAPTOP

This device is designed to organize automatic recording of audio signal from a telephone line and convert it to mp3 format so that you can then listen to it. Recording and encoding to mp3 format is carried out by a computer with installed software.

The hardware part, implemented on the PIC16F84 microcontroller of the company, monitors the status of the telephone line, extracts the audio signal, and sends a control signal (telephone line status) to the computer using the USB port (RS232-USB).

The diagram of the device is shown in the figure.

The software installed on the computer receives the status of a telephone line, controls the process of recording an analog signal (converting to WAV format) and, after recording is completed, recodes the data into mp3 format (the library is used to encode mp3). The program keeps track of the date and time of the start and end of the recording, which is also reflected in the names of the created files.


Application window for recording telephone conversations

The telephone line monitoring circuit measures the voltage on the telephone line when the telephone is on-hook and is greater than 15 V (approximately 50 V). When the user picks up the handset of the telephone, the voltage drops below 15 V. This moment is used to detect the use of the telephone line.

An isolation transformer from an old modem is used to isolate the audio signal. As well as two 1N4148 diodes to limit the output voltage of the transformer to 0.6 V, a capacitor and a resistor.

The microcontroller checks the status of the telephone line every 0.2 s using the line monitoring node described above. If the optocoupler is “closed” for more than 0.15 s, this means that the line is in use and the microcontroller issues the “R” (Rec - Record) command to the running application on the computer. Otherwise, the command "S" (Stop - Stop) is sent. According to the commands, the application on the PC operates. The microcontroller uses the serial protocol to transmit commands, the module on the PL-2303 chip converts the serial protocol to USB. Of course, it was possible to use the V-USB library, the task would have been solved a little easier and it would have been possible to use only one AVR controller, instead of the PIC16F84 and PL-2303 we use.

List of used components

Appearance of the device



  • Easier to install. AudioSpy or SpyRecord and use TWO capacitors, TWO resistors and TWO zener diodes to connect to the computer's audio input.
  • I agree llllll and even simpler, I had a program, I did it all using a modem, and why connect the PIC to the computer if everything is in the computer?
  • The protection of such devices should be given attention, however, the author indicated the varistor only as an option. lllll, do you have two zener diodes for protection? But there is no full galvanization? Sirak, Your option is interesting, can you elaborate? I ask everyone for a practical purpose, for some reason I was previously indifferent to this issue, interest was shown only now. I googled, but didn't really find anything on the topic.
  • The telephone line is connected through isolation capacitors (one for each wire. Next, a voltage divider and two back-to-back zener diodes (protection). You can completely isolate the line by turning on an isolation transformer (a 1-5 microfarad capacitor in series with the primary winding is non-polar.)
  • llllll, please post the schematic with the denominations, so it's clear how to do it. Only the option with a trance, without complete galvanic isolation will not work, there is no desire to repair the computer after thunderstorms. And after hitting the "left" voltage on the phone line.
  • it was a program without any electronic devices, using a modem connected to the telephone line and recording conversations, I will look for this program and post it here, I remember that I downloaded the program from the site http://www.softnavigator.ru/
  • here is the program Modem Spy v3.6.1 Program for recording telephone conversations. It can automatically record all incoming phone calls - date, time, the conversation itself, as well as determine and fix the caller's number (although only the Western standard for determining the CID number is supported). It is also possible to record in manual mode, and not only telephone conversations, but also those that are conducted indoors (from a microphone connected to the sound card). The recording can be made in WAV, MP3 and other audio formats, the resulting recordings can be listened to both through a sound card and through a phone. In addition, it is allowed to record outgoing calls, as well as sending recorded conversations by e-mail. Another curious detail is that it is permissible to make notes about a particular entry. Unique features * Automatic recording of all telephone conversations * Recording from a microphone in voice recorder mode * Playback of recorded messages to a telephone line or through a sound card * Built-in automatic gain control (AGC) * Send recordings by e-mail with a single mouse click. * Identification of the caller's number (for some modems) and logging of calls * The program's friendly interface allows you to take quick notes about the call. * Optional notification of the interlocutor about the recording of the conversation. This is required in some countries. * There is also a Super Spy mode for invisible call recording. * You can also convert your recordings to any voice format - MP3, WAV, etc. * The size of the program is only 300 kb. http://depositfiles.com/ru/files/1718134