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If you are interested to build TV transmitter for your electronic project this Advanced TV Transmitter With Sound designed by Tetsuo Kogawa could be good idea for you. TV transmitter consists of of the two sections: video transmitter and audio amplifying. Both of them actually is transmitters. The main one generates video carrier while the smaller one generates the exact 4.5 (5.5 in some countries) MHz FM audio carrier. When it is supplied to the main section, the combination generates the audio carrier that is the total of the video frequency plus 4.5 MHz (this is the same in the US but different in other countries: 3.5 in the UK, 5.0 in Italy, 5.5 in Australia and so on: see the channel plans). The Audio section (1)Coil: The most difficult point is the coil. You can use any type of coil as long as it fits the inductance. But the size of coil for 4.5 MHz is quite large if you use usual type of coils. Here I will use Ferrite Troidal core that is made by Amidon Associates. Wind 0.2 ECW (enamel-coated wire) around the "FT-50-43" (Amidon) in 24 turns. (2)Transistor: You can use popular ones such as 2SC2001, 2SC1815, 2SC1907, etc. But you must keep the pins (E, C, B). How to adjust: Connecting the prove of the frequency counter at "#to the audio-in". Then adjust "Trimer cap. (80PF)" as the frequency counter shows exactly 4.5MHz. Sometimes, you have to add some capacitors (depending 100-1000PF) at the "E(mitter)" position of the transistor in order to adjust the frequency.

pıc basic projects: 30 projects using pıc basıc and pıcbasıc pro

This RF power amplifier is based on the transistor 2SC1970 and 2N4427. The output power is about 1.3W and the input driving power is 30-50mW. It will still get your RF signal quit far and I advice you to use a good 50 ohm resistor as dummy load. To tune this amplifier you can either use a power meter/wattmeter, SWR unit or you can do using a RF field meter. RF Amplifier Assembly Good grounding is very important in a RF system. I use bottom layer as Ground and I connect it with the top with wires to get a good grounding. Make sure you have some cooling at the transistor. In my case I put the 2SC1970 close to the PCB to handle the heat. With good tuning the transistor shouldn't become hot. RF Amplifier Printed Circuit Board You can download a pdf file which is the black PCB. The PCB is mirrored because the printed side side should be faced down the board during UV exposure. To the right you will find a pic showing the assembly of all components on the same board. This is how the real board should look when you are going to solder the components. It is a board made for surface mounted components, so the copper is on the top layer. I am sure you can still use hole mounted components as well. Grey area is copper and each component is draw in different colors all to make it easy to identify for you. The scale of the pdf is 1:1 and the picture at right is magnified with 4 times. Click on the pic to enlarge it. Low-Pass Filter Some of you might want to add a low-pass filter at the output. I have not added any extra low pass filter in my construction because I don't think it is needed. You can easy find several homepages about low pass filter and how to build them.

Çocukluğumuzun meşhur dizisi Knight Rider yada kara şimşek’deki siyah arabanın önündeki led efektini sanırım hepimiz biliriz. Bu uygulamada B,C,D portları kullanarak 18 led ile yürüyen ışık devresi yapılmıştır. Kodlarda yapacağınız değişiklik ile led sayısını artırıp azaltabilirsiniz. PHP Kodu: #include <16f877.h>#fuses XT,NOWDT,NOBROWNOUT,NOLVP,NOPUT,NOWRT,NOCPD#use delay(clock=4000000)//Tüm programdaki gecikmeleri ayarlama#define gecikme 30 void main (){int i,j;    while(1)   { // İLERİYE SAYIM       // B portu için      j=1;  //kaydırma işlemi için sayı değeri      for(i=0;i<8;i++)      {  output_b(j);      // j sayı değeri B portunda         j=j<<1;         // j sayısını  1 bit sola kaydır         delay_ms(gecikme);  //ledin yanık kalma süresigecikme veriliyor      }   // C portu için      output_b(0);//son kalan portb bilgisi sıfırlanır      j=1;      for(i=0;i<8;i++)      {  output_c(j);         j=j<<1;         delay_ms(gecikme);      }      // D portu için      output_c(0);//son kalan portc bilgisi sıfırlanır      j=1;      for(i=0;i<8;i++)      {  output_d(j);         j=j<<1;         delay_ms(gecikme);      }      //İLERİYE SAYIM SONU     //GERİYE SAYIM D PORTU İLE BAŞLAR      j=128; //kaydırma işlemi için sayı değeri     for(i=0;i<7;i++)      {  j=j>>1;    // j sayısını  1 bit sola kaydır         output_d(j); //j sayısı çıkış portunda         delay_ms(gecikme); //ledin yanık kalma süresi      }      output_d(0);//son kalan portd bilgisi sıfırlanır      j=128; //kaydırma işlemi için sayı değeri     for(i=0;i<7;color: #

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Willem EPROM Programmer 2009

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