Power Amplifier

In this section discuss about the series of mini fm transmitter, with broadcast coverage of about 300-400 meters. when using a 9 volt working voltage, the transmit power of about 300 meters and when using the working voltage 12 volts, the range of about 400-450 meters, depending on the antenna you use. This scheme of simple fm transmitter For L1 and L2 windings 5 times the wrap, you can use a pen to fill melilitnya so neat and after lepaslah content of these pens. C5 is used for placement of broadcasting frequencies, can be tuned between 88-108 mhz, to reach further use steering antenna or Yagi antenna. Part List C1 = 0.001uF C2 = 5.6pF C3 = 10uF C4 = 10uF C5 = 3 - 18pF Adjustable capacitor R1 = 270R R2 = 4.7K R3 = 10K R4 = 100K R5 = 4.7K R6 = 4.7K Q1 = 2N2222A Q2 = 2N3904 L1 = 5 turn L2 = 5 turn

FM Modulator circuit is a simple FM modulation circuit using IC 555, where the resulting modulated signal has a tenuous meeting depends on the signal frequency information.  The resulting signal can be spelled out quite nice and stable so that the result will be more perfect. No winding or inductor in series modulator, so you do not need to bother to make a winding and calculate the value of the coil that you created it. With this circuit the desired value of frequency modulation can be obtained easily by calculating the frequency of IC 555 in general, which is determined by the resistor 6.8 K and 3.3 K and 0.1 UF capacitor. To obtain the other frequencies of your stay replace one or all three components. Actually fm modulator ic 555 circuit is very simple though, but I think it reliable enough to handle a simple application purposes that do not require a big power or a very high frequency. But if you want more power you can add the RF amplifier circuit at the output of this circui...

AM Transmitter circuit  To this powerful AM transmitters are huge, using ceramic tuning 3.587 mhz resonator and resonator filters are also sold with a value of 5.5 mhz, 7.7 mhz and 10.7 mhz. Distance transmitter range is approximately 2-4 km. the working principle of this circuit are filter resonator/ceramic filters raise the frequency of the value of the resonator filter. This frequency is amplified by the transistor can be changed t1. Frequency so need C7 as a regulator / placement. sound signal superimposed over the audio transformer.frekuensi which awakened by resonator filters and t1 is fed to the next amplify strengthened so as to achieve the desired power passed to antenna. t2 and t3 as a buffer as a final power amp. AM Transmitter Schematics AM radio / receiver circuit For AM radio because it's hard to find IC ZN 414 then now could be replaced with the equivalent of IC MK 484. Frequency coverage between 550 kHz-1600 mhz...

FM Radio Receiver IC TDA 7012T is very simple, but Radio This FM receiver has good sensitivity and selectivity. Single Chip TDA 7012T FM Receifer is to build an FM receiver requires a few additional components. Feature contained in FM receiver IC TDA 7012T is quite tempting to an FM receiver. Among features an FM receiver TDA 7012T is a low-voltage applications micro affability arrangement (MTS), Frequency Loked Loop (FLL) to 76 KHz range and selectivity of FM receiver with RC Filter. In an article by FM Radio Receiver IC TDA 7012T can be seen in the FM receiver circuit which can be made​​. TDA7012T- Mini FM received Schematic Part List R1 = 8kΩ2 R2 = 10kΩ R3 = 390Ω C1,C3 = 10nF C2,C6,C9,C16 = 100nF C4 = 33pF C5 = 25pF trimmer C7,C10 = 1nF5 C8 = 820pF C11 = 1nF C12 = 68pF C13 = 220pF C14 = 47μF 10V C15 = 3nF3 L1 = 36nH L2 = 1μH, IC1 = TDA7021T

Playing cars that are controlled via radio signals is an interesting game. The much-loved toy cars children, plus a simple circuit will be the ideal toy car. This circuit families use traditional digital CMOS IC which requires very little electrical current, so it will not burden the original toy car performance. In this system, radio signals are not transmitted continuously but only generated when the controller sends a command to the left / right or forward / backward, and even then only a radio-frequency discontinuous, so is sending pulses of radio wave frequency. The number of pulses sent represent commands sent, GO command is represented with 8 pulses, is represented with 16 pulses LEFT, RIGHT DOWN 32 pulses and 64 pulses. Commands that can dikirimk is a combination of 2 orders once gus, which is a combination of command forward / backward and right / left, for example, could be sent forward orders and left once gus, in this case the number of pulses sent is 24, ie the sum of the ...

Here's a simple VHF FM transmitter that could be used to play audio files from an MP3 player or computer on a standard VHF FM radio. The circuit use no coils that have to be wound. This FM transmitter can be used to listen to your own music throughout your home. When this FM transmitter used in the car, there is no need for a separate input to the car stereo to play back the music files from your MP3 player. To keep the circuit simple as well as compact, it was decided to use a chip made by Maxim Integrated Products, the MAX2606 [1]. This IC from the MAX2605-MAX2609 series has been specifically designed for low-noise RF applications with a fixed frequency. The VCO (Voltage Controlled Oscillator) in this IC uses a Colpitts oscillator circuit. The variable-capacitance (varicap) diode and feedback capacitors for the tuning have also been integrated on this chip, so that you only need an external inductor to fix the central oscillator frequency. USB FM transmitter schematics It is poss...

The series that we will make this is a special electronic circuit can be used to detect the presence or absence of signal AF / RF. The circuit is very neat and simple to make. Costs it takes quite cheap. If you are already assembling this circuit, then with easy reader determine whether there is AF or RF signal at a particular section of a circuit. Basic circuit uses an audio amplifier and a loudspeaker with switch input for AF and RF signals. The whole device can be made small as possible so it can be included in a container to maintain security. Audio amplifier section in this series created by IC TDA 2822M, with low stereo power amplifier in 8-pin mini-DIP. IC is used as a bridge cofiguration to shrink to 250 mW output power, loudspeaker handle 4 ohm, 500mW. The current required is less than 10mA with voltage of 3V battery. RF-AF signal detector schematics How it Works circuit When the selector switch in the AF position, wor...