Communication device. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Measuring technology

 Comments on the article

When installing communication lines, fitters have to use various devices. A set of equipment often takes up a lot of space and weighs a lot. In order to facilitate the work, the author has developed a multifunctional device.

I work as a dispatcher. In my work I have to deal with measurements, with the operation of equipment (telephones, low-frequency amplifiers), with the "ringing" of communication cables, with the operation of automation, with the repair of dispatching equipment. For work, I had to use many different devices, including bulky ones.

The proposed device was developed as a universal and small-sized device for many types of communication work, and can also be used as a test device for radio amateurs. Its dimensions are 200x180x70 mm, weight is about 2 kg

Instrument capabilities:

• measurement of direct and alternating voltages up to 250 V with a pointer device;
• measurement of resistance from 0 to 10 kOhm with a pointer device;
• a probe on LEDs allows you to check the health of transistors, diodes, capacitors, resistors up to 5 kOhm, as well as the health of the mounting conductors;
• a 900 Hz generator with the ability to adjust the output signal level allows you to check the correct operation of the VLF, the performance of dynamic heads and telephone capsules;
• a probe with a 3,5 V incandescent lamp and a 4,5 V power supply allows you to check the health of mounting conductors and resistors up to 30 Ohm;
• a 26 V incandescent lamp allows you to check the presence of voltage up to 30 V in the dispatch communication equipment;
• The telephone set assembly allows the device to be used as a complete telephone set with dialing and receiving a ringing signal. The built-in amplifier allows you to listen to the subscriber on a dynamic head;
• the same telephone set with 9 V power supply allows you to "ring out" multi-core telephone cables up to 0,5 km long. You can "ring" the cables through the handset, as well as listen to your partner on the speakerphone;
• the built-in low-frequency amplifier allows you to connect various devices to it through a switch, in particular, a prefix-finder hidden wiring, as well as to conduct loud-speaking control when talking on the phone and when "ringing" communication cables.

(click to enlarge)

On fig. 1 shows the main scheme of the device, and in fig. 2 - diagrams of the blocks included in it. The device does not contain scarce parts and assemblies. It uses transistors of the MP37, MP41, KT315, KT361, KP303 and GT308 series.

(click to enlarge)

Purpose of the blocks: A1 - LED probe; A2 - generator with a frequency of 900 Hz; A3 - telephone set (fitter handset); A4 - hidden wiring finder; A5 - low frequency amplifier.

Consider the operation of the device and the passage of signals in various modes.

1. Measurement of DC and AC voltages up to 250 V. Switch SA1 must be in position "1". The current flows through the circuit: probe X1, moving contact of switch SA1.1, diode VD1, measuring head PA1, resistor R1, moving contact of switch SA1.2, probe X2.

2. Measurement of resistance up to 10 kOhm. Switch SA1 must be in position "2". The current flows from the positive terminal of the GB1 battery through the SA1.2 switch contact, the X2 probe, the measured resistor, the X1 probe, the SA1.1 contact, then along the VD1PA1R3R4 circuit and through the SA1.3 contact to the negative terminal of the GB1 battery.

3. LED probe. The switch position SA1 for this mode is "3". Probes X1 and X2 are connected to contacts 1 and 2 of block A1. The A1 unit is powered by the GB1 battery.

4. Generator with a frequency of 900 Hz. Switch position SA1 - "4". Unit A2 is powered by battery GB1. The generated signal comes from contacts 1 and 2 of block A2 through contacts SA1.1, SA1.2 to probes X1, X2, respectively.

5. Probe with a 3,5 V incandescent lamp. The position of the SA1 switch is "5". The current flows from the positive terminal of the GB1 battery through the SA1.2 contacts, the X2 probe, the circuit under test, the X1 probe, the SA1.1 contacts, the HL1 incandescent lamp, the SA1.3 contacts to the negative terminal of the GB1 battery.

6. Control lamp for 26 V. The position of the SA1 switch is "6". Lamp HL2 is connected directly to the probes X1, X2 through contacts SA1.1 MSA1.2.

7. Telephone set (TA). Switch position SA1 - "7". The contacts of block A3 are connected to probes X1 and X2. You can talk through the handset - microphone BM1 and telephone BF1 block A3. SA2.1 and SA2.2 in this block are dialer contacts.

8. If you put the SA1 switch in position "8", the device can be used to "diagnose" communication cables. In this mode, a telephone set is used (block A3). Power is provided by two batteries connected in series GB1 and GB2. Current flow path: GB2 positive battery terminal, SA8 switch pin 1.2, X2 probe, tested communication line, X1 probe, pin 8 SA1.1, terminal 1 of A3 block, terminal 2 of A3 block, terminal 8 SA1.3, negative terminal GB1 batteries.

9. Low frequency amplifier. When the switch SA1 is set to position "9", the X1 and X2 probes will be connected to the ULF input. The amplifier is switched on by the SA4 toggle switch, which is combined with the level control (variable resistor R1 in block A5). Switch SA3 is installed to protect the input of the LF amplifier from the ringing voltage during the operation of the SLT, i.e. the signal is fed to the input of the amplifier only after the SLT tube is removed. The operating mode of the amplifier depends on the switch SA2. Position 1 corresponds to the mode with an open input, 2 - with a closed input (the signal passes through the capacitor C1), and position 3 is intended for loud-speaking control of a conversation over a SLT and during the "ringing" of communication cables. The prefix for finding hidden wiring (block A4) is connected via the XZ connector directly to the input of the amplifier. The console is powered by a GB3 amplifier battery.

10. In the switch position SA1 "10" the device performs the function of a voltmeter with a measurement limit of 30 V.

Measuring head RA1 - M4203 milliammeter with a drain of a total deviation of 5 mA. Lamp HL1 - 3,5 V and current 0,26 A, HL2 - 26 V 0,12 A. Batteries GB1 and GB2 consist of three elements of size R14 each. GB3 battery - any 4,5 V battery, for example, 3R12. Dynamic head VA1 - GDSh-2 with a resistance of 8 ohms. Details of the A3 handset: BM1 microphone - carbon MK-16-U, BF1 telephone capsule - TK-57, SA2 dialer - "Electronics NK-03".

Structurally, the device is made in the case "Radio Amateur Kit" (Fig. 3). Only the body, front and rear aluminum false panels were used. On the front panel there is a measuring head PA1, two sockets for lamps HL1 and HL2, switches SA1, SA2 of the main unit and a variable level adjustment resistor R1 (block A5).

On the rear panel there are two connectors for connecting a set-top box for finding hidden wiring and for turning on a telephone headset (handset or headphones with a microphone), two variable resistors for adjusting the output level of the 900 Hz generator (R1 in block A2) and zeroing when measuring resistors (R4 of the main block), jacks for connecting instrument probes and the "Talk-call" switch of the telephone set (SA1 in block A3).

Author: L.Sidorov, Yartsevo, Smolensk region

See other articles Section Measuring technology.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Controlling objects using air currents 04.05.2024

The development of robotics continues to open up new prospects for us in the field of automation and control of various objects. Recently, Finnish scientists presented an innovative approach to controlling humanoid robots using air currents. This method promises to revolutionize the way objects are manipulated and open new horizons in the field of robotics. The idea of ​​controlling objects using air currents is not new, but until recently, implementing such concepts remained a challenge. Finnish researchers have developed an innovative method that allows robots to manipulate objects using special air jets as "air fingers". The air flow control algorithm, developed by a team of specialists, is based on a thorough study of the movement of objects in the air flow. The air jet control system, carried out using special motors, allows you to direct objects without resorting to physical ... >>

Purebred dogs get sick no more often than purebred dogs 03.05.2024

Caring for the health of our pets is an important aspect of the life of every dog ​​owner. However, there is a common assumption that purebred dogs are more susceptible to diseases compared to mixed dogs. New research led by researchers at the Texas School of Veterinary Medicine and Biomedical Sciences brings new perspective to this question. A study conducted by the Dog Aging Project (DAP) of more than 27 companion dogs found that purebred and mixed dogs were generally equally likely to experience various diseases. Although some breeds may be more susceptible to certain diseases, the overall diagnosis rate is virtually the same between both groups. The Dog Aging Project's chief veterinarian, Dr. Keith Creevy, notes that there are several well-known diseases that are more common in certain breeds of dogs, which supports the notion that purebred dogs are more susceptible to disease. ... >>

Random news from the Archive The Pentagon is developing an orbital station 08.07.2019 The Department of Military Innovation (DIU) of the US Department of Defense announced a competition to develop an orbital station that could be used for experiments and cargo storage. According to the list of requirements that the Pentagon makes to potential bidders, a promising orbital station must be suitable for space construction, microgravity experiments, training, testing, cargo storage and transportation, as well as for certain "other functions." As part of the tender, participants must design and build a prototype of a small robotic orbital station with a volume of one cubic meter. A promising station should be suitable for handling cargo or any other payload weighing up to 80 kilograms. The onboard power supply must provide 1 kilowatt of energy, and the station's communication systems must provide data exchange at a speed of at least 100 kilobits per second. The competition will be held in several stages. First, we will talk about the development of the project of the station. In 2020, the development and launch of prototypes of orbital stations should begin - from the moment a contract is signed to the launch of prototypes, according to the requirements of the military, no more than two years should pass. Prototypes should be assembled on a modular basis and provide for the possibility of subsequent upgrades. Among the functions of the station, the Pentagon also included the reception of people on board. In addition, the station must be able to change orbit, perform work outside low Earth orbit, dock with other manned and unmanned spacecraft, and assemble other objects in orbit using one or more robotic arms.

Other interesting news:

▪ Perhaps there are planets inhabited by intelligent dinosaurs

▪ Non-melting ice cream

▪ Palette Cube accurately detects colors

▪ Hard drives with FC-MAMR technology

▪ New router for communication networks DS33Z41

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the Radio Control website. Article selection

▪ article Nature has no bad weather. Popular expression

▪ article Who are trichologists? Detailed answer

▪ article Linear pipeline. Standard instruction on labor protection

▪ article LED device Flashing lights. Encyclopedia of radio electronics and electrical engineering

▪ article Extraordinary memory. Focus Secret

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024