Circuit Power transmitter of communitarian wireless TV lm1889 audio and video

lm1889

Potent circuit for transmitter of communitarian TV with lm1989 in vhf channels, video link for DVD, computer or video camera transmitter

This small circuit transmitter processes the signs of audio of a sound table or microphone, and the signs of video of a camera, or still the audio signs and video of a DVD, Video-cassette or even it sweats her video plate has an exit of composed video, you can transmit direct of your computer. Playing them in a channel free from the strip of VHF.

These signs can be irradiated with a common antenna and captured in an it distances of until about 500 meters that it is the most appropriate for urban areas, reminding that and necessary to be a lot of caution and careful for not interfering in frequencies of other issuing, as well as to emergency services. Depending on the local conditions (existence or not of obstacles). Fed with tensions from 12 to 15 Volts, the circuit has excellent I carry out so much in the emission of monochrome signs, as in colors. An important point of this project ‘the easiness with that he can be set up and adjusted, since only two coils are used. Ideal to be used with surveillance cameras turning the without thread.

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As it Works the tv video and audio transmitter with lm1889n

The heart of this circuit transmitter ‘is the integrated circuit LM1889N of National Semiconductor, that consists of a Modulator of Video for TV in an involucres of 18 pins DIL.

This integrated circuit ‘used in videocassettes and videogames, exactly to process the image information and sound, so that they can be played in a channel free from the strip of VHF.

As it is component that ‘used in commercial equipments, besides the reliability, we have a certain obtaining easiness. The readers, with luck, until they can find this available component in an old videogame that it is out of use, and you take advantage of it to set up your station communitarian. count all the necessary stages to the processing of the video signals and audio of a transmitter of signs of TV.

The coil L1 together with the capacitor in parallel, it generates the sign of 4,5 MHz that, modulated with the sound, it should be separate from the bearer of video of this frequency. Like this, the adjustment that should do in this coil it simply consists in you take it to 4,5 MHz, in way we obtain it sound.

The audio modulation ‘done by a varicap in a very simple way, so that the intensity of the audio sign obtained in most of the exits of the sound table it should provide a good reproduction.

The video sign, that obtained ‘of the video exit of any camera, videocassette, DVD, applied in the pin 13 of the circuit integrated after going by an amplification stage with two transistors.

This sign will modulate in width the video bearer whose frequency certain ‘for L2 and the capacitor in parallel.

We should adjust the frequency of this oscillator for the channel free from the strip of VHF, usually a channel baixo(2 to 6) in that the broadcasting station will operate.

The exit of RF, obtained in the pin 11 mischievous ‘to an amplifying stage with a transistor and of this for the antenna expresses or a telescopic antenna, in case the transmission is of short reach. Observe that in the modulation of audio of this circuit, the sign generates two subportator being below a 4,5 MHz above the frequency of the channel and other 4,5 MHz.

As one of them not eliminated ‘, she can cause interferences in the adjacent channel. That means that you should choose a free channel in your place, but that doesn’t have adjacent channels operating.

The power supply of the circuit can be made with tensions of 12 (7812) or 15(7815) Volts of a source with at least 1A and excellent filter. A deficient filter in this type of so much circuit can provoke snores in the sound, as undulations in the image.

Suggestion of power supply for circuit using the ic 7812

Power Supply For The Tv Transmitter Using The Integrate Circuit 7812

Schematic for assembly of the tv transmitter with lm1889n

Circuit Schematic For The Tv Transmitter With Lm1889

Assembly of the circuit of the tv transmitter

The healthy resistors of 1/8W or larger. The power source so much can be the one of 12V/1A, as it can be made a modification to operate with 15V, being enough for that to change the transformer and the integrated circuit. The circuit plate printed for the assembly ‘shown below in the illustration. The coils, as always, are the elements more critics of the project. L1 ‘formed by 40 you exhale of thread enameled fine (30 to 34) in a form of 5 diameter mm and 18 height mm, with nucleus of adjustable ferrite. The form for this coil can be obtained in old radios and televisions. The coil L2 that determines the frequency of the channel can have from 2 to 6 you exhale of thread 18 to 22, in used similar form her for L1. For 2 or 3 you exhale we will have the operation in the high channels of VHF, between the 7 and the 13, and for 4 to 6 you breathe the operation it will be among the channels 2 and 6. For the entrance of audio and video important ‘to use armored threads and appropriate connectors. For the antenna to use a connector for cable of 75 Ohms. The transmission section should not be in the same box that the source. The transmitter should be shielded for larger operation stability and to avoid the reception of noises that affect the transmission. The trimpot P1 has for purpose to adjust to component DC of the video sign, important to obtain the maximum revenue in the transmission.

Adjust alignment of the video, audio, the coils, antenna and frequency of the operation

To test and to adjust the transmitter, call in your entrance the exits of audio and video of a videocassette with any ribbon of good quality. Use appropriate cables. Tie the transmitter and, in that she intend to do the operation. The antenna of the transmitter can be a piece of some centimeters of covered common thread. Adjust the coil initially L1 so that the sign of maxim image intensity is captured. Adjustment the way trimpot to obtain the best image. Then, adjust slowly the coil L2 until obtaining the sound sign. Obtaining the sound sign, retouch the tuning of way L1 to obtain the maxim transmission. If it has difficulties in obtaining the tuning in the wanted channel, alter the value of C7 or I number it of you exhale of L1. If it has difficulties in tuning in the sound, alter C6 or then the number of you exhale of L2.

Printed Circuit Board For Tv Transmitter Lm1889N

The board has dimensions of 11,2 x 7,0 cm .

 

Proven the operation, make the connection of the definitive antenna (it expresses or it interns) and re-do the way fittings to obtain the best transmission quality. After that, it is only to operate the station.

LIST OF MATERIAL
Power supply

  • CI1 – 7812 or 7815
  • D1 D4 1n4004 or equivalent
  • C1 C4 – 10NF
  • C5 – 2200µF TO 4700µF / 50 V
  • C6 – 100NF
  • C7 – 100µF 35V
  • C8 – 100NF
  • L1 – Shock of RF 100µH / 1 THE
  • T1 – Transformer, primary in agreement with the net (110/220) and secondary from 18 to 24V / 1A
  • Several – printed circuit board, threads, box, etc.

Transmitter
Semiconductors:

  • Cl1LM1889– Integrated Circuit – Modulator of Video
  • Q1, Q2, Q4 – BC547 or equivalent
  • Q3 – BD135 or equivalent, example 2n2218 (different Pinage)
  • D1BB809 VARICAP or equivalent

Resistors 1/8W, 5%:

  • R1, R15 – 82 Ohms-
  • R2 – 120 K Ohms
  • R3 – 27K Ohms
  • R4 – 1,2 K Ohms
  • R5, R13, R14 – 270
  • R6 – 470 Ohms
  • R7 – 56k Ohms
  • R8 – 68k Ohms
  • R9 – 220 K Ohms
  • R10 – 2,7 K Ohms
  • R11, R17 – 1 K Ohms
  • R12, R16. R19 – 10 K Ohms
  • R18 – 47 Ohms x 1W
  • R20 – 22 K Ohms
  • P1 – 10 K Ohms trimpot

Capacitors:

  • C1 – 4,7µF/1 6V – ELECTROLYTIC
  • C2, C3 – 10µF/1 6V – ELECTROLYTIC
  • C4, C8 – 1 nF – ceramic
  • C5 – 120 pF – ceramic
  • C6 – 47 pF – ceramic
  • C7 – 56 pF or 47 pF – ceramic

Several:

  • L1, L2 – Coils – L1 – 0.3µH and L2 – 7 to 13µH.
  • XRF – Coil 100µH – to see text.
  • Several -printed board circuit , entrance Jacques and output of signs, box for assembly, power source, forms for the coils, enameled threads, etc.

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About the author
Xtronic.org blog author. Electronics technician for the technical school of Brasilia - Brazil. Interested in electronics, circuits and technology in general.
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29 thoughts on “Circuit Power transmitter of communitarian wireless TV lm1889 audio and video”

  1. Hi tony
    How did you assumed/found the area of propagation(500meters)?
    please i would like to know the corresponding equations!! because i want to increase the propagation area!
    Thanks, hope i will hear from you

    Reply
  2. hola Antoni qisiera que me enbiaras algunos diagramas de audio y video,he soñado con tener algun dia una tv transmitin ,y ya que beo las fasilidades de heser mis aparatos yo mismo eso esta de marabilla., saludos y te felicito por tus proyectos.,

    Reply
  3. Hi dear,
    Please send me the total description of this projects. because i am going to do as a my final projects.
    pls.

    Reply
  4. I m making this video transmitter a major project so can you plz send me all the required data related to the project i.e. synopsis, report etc

    Counting on you please

    Reply
  5. Hi, Toni

    I work on a major project in my university, which is to optical transmit and receive the audio and video signals from digital camera to a PC….. So can u send me the project detail i.e. synopsis, report etc

    Reply
  6. hola como están algún miembro de esta red me puede ayudar con esto ando buscando un transmisor en uhf para canales 16 al 36 y un amplificador para tv en uhf 10 wattio y un vhf los diagrama espero alguna ayuda gracias
    mail :[email protected]

    Reply
  7. I m making this video transmitter as major project so plz send me all the required data related to the project i.e. synopsis, report etc

    Reply
  8. Hi, Toni
    I m making this video transmitter as major project so plz send me all the required data related to the project i.e. synopsis, report etc

    Reply
  9. Hi. tony…..!!! I work on a major project in my university, In which i have to wireless transmit and receive the audio and video signals from digital camera to a PC….. So can u send me the project details….. Please….. please….

    Reply
  10. Olá Tony. Vejo que você estoudou no Brasil. Gostei muito do seu site. Se você puder, por favor mande-me mais esquemas de amplificadore de RF.
    Abraço,
    Bambam

    Reply
  11. Hi, Toni
    I m making this video transmitter as major project so plz send me all the required data related to the project i.e. synopsis, report etc

    Reply
    • hello.
      [ i need the orginal map[ standard
      please sumbit the orginal mapping method for me
      circuit power transmitter……_lm 1889 audio and video

      Reply
    • hello.mr toni.[ i need the orginal map[ standard
      please sumbit the orginal mapping method for me
      circuit power transmitter……_lm 1889 audio and video

      Reply
    • Hi TONY
      How did you found the propagation area(500meters)?
      I would like to know the corresponding equations that you went through, because i want to increase the propagation area!
      Thanks, hope i will hear from you!

      Reply
  12. I m making this video transmitter as major project so plz send me all the required data related to the project i.e. synopsis, report etc

    Reply

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