Do More

Super heterodyne receivers have been mass-produced since around 1924, but for reasons of cost did not become successful until the 1930s. Before the second world war other, simpler receiver technologies such as the TRF receiver and the regenerative receiver were still widespread.   Circuit diagram :   Tuned Radio Frequency (TRF) Receiver Circuit Diagram   The circuit described here is based on the old technology, but brought up-to-date a The most important part of the circuit is the input stage, where positive feedback is used to achieve good sensitivity and selectivity. The first stage is adjusted so that it is not quite at the point of oscillation. This increases the gain and the selectivity, giving a narrow bandwidth. To achieve this, the potentiometer connected to the drain of the FET must be adjusted very carefully: optimal performance of the receiver depends on its setting. In ideal conditions several strong stations should be obtainable during the day using a 50 cm antenn...

Hello! in this post I will show a remote control receiver, I tested this circuit with an approximate distance of 4 meters and it worked perfectly, the spread of this circuit is that it can be triggered by remote control of multiple devices, I tested with two remote controls one tV receiver and a satellite dish, every time you press a key on the remote, the LED will light up and trigger the relay, the relay output you can connect any device you want to control the 1N4148 diode D4 is also You can add more channels to the circuit, just by connecting the reset of the integrated circuit in 4017 and adding another exit other relés.Assim each pulse sent to the receiver, trigger a relay! The relay coil has voltage according to the circuit power! Remote Control Receiver Circuit Diagram The receiver used is three terminals, commonly used in television sets! See the figure below:

Circuit Diagram Description This is basically a crystal radio with an audio amplifier which is fairly sensitive and receives several strong stations in the Los Angeles area with a minimal 15 foot antenna. Longer antennas will provide a stronger signal but the selectivity will be worse and strong stations may be heard in the background of weaker ones. Using a long wire antenna, the selectivity can be improved by connecting it to one of the taps on the coil instead of the junction of the capacitor and coil. Some connection to ground is required but I found that standing outside on a concrete slab and just allowing the long headphone leads to lay on the concrete was sufficient to listen to the local news station (KNX 1070). The inductor was wound with 200 turns of #28 enameled copper wire on a 7/8 diameter, 4 inch length of PVC pipe, which yields about 220 uH. The inductor was wound with taps every 20 turns so the diode and antenna connections could be selected for best results which turn...

TDA 7012T FM Radio Receiver FM Radio Receiver IC TDA 7012T is very simple, but it has an FM radio receiver sensitivity and good selectivity. Single Chip FM Receifer cool name of IC TDA7012T 7012T TDA 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​​. FM Radio Receiver with IC TDA 7012T From the picture above components to make the FM Radio Receiver IC TDA 7012T as follows: 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 Ho...

Block diagram of AM transmitter and receiver with explanation AM Transmitter : Transmitters that transmit AM signals are known as AM transmitters. These transmitters are used in medium wave (MW) and short wave (SW) frequency bands for AM broadcast. The MW band has frequencies between 550 KHz and 1650 KHz, and the SW band has frequencies ranging from 3 MHz to 30 MHz. The two types of AM transmitters that are used based on their transmitting powers are: ·          High Level ·          Low Level High level transmitters use high level modulation, and low level transmitters use low level modulation. The choice between the two modulation schemes depends on the transmitting power of the AM transmitter. In broadcast transmitters, where the transmitting power may be of the order of kilowatts, high level modulation is employed. In low power transmitters, where only a few watts of transmitting power are required , low...

TRANSMITTER AND RECEIVER AM SUPERHETERODYNE Distribution of information from one place to another can be done with a wide - variety of ways. As one way to distribute information in a radio communications technique, was made with modulated AM transmitter rise. The term superheterodyne stands for supersonic heterodyne, which can be interpreted as the generation of mixed frequencies above the hearing. Transmitter Receiver -AM-Transmitter AM transmitter is a transmitter that utilizes analog modulation techniques are AM (Amplitude Modulation), to transmit information signals. The source carrier is driven by a crystal oscillator at the carrier frequency or multiples below. The amount of output frequency can be adjusted by changing the value of L and C. Cultivated constant frequency emitted wave output generated for the better. This was followed by a buffer amplifier tuned. With the buffer labored to frequencies generated by the oscillator constant. Signal information entered on this circuit ...

source: Kyriakos Kontakos Tendency of catering: + 12V DC Frequency of reception at AM: ~27MHz   Materially: The resistances are 1/4W. R1, R3, R5 100W R2 56KW R4 39KW R6 560W R7, R11 6,8KW R8 220W R9 2,2KW R10 5,6KW R12 10KW logarithmic pontesiometer R13 1KW R14 10W C1 150pF ceramic C2 39pF ceramic C3, C5 12pF ceramic C4 56pF ceramic C6, C7, C8, C9, C10, C11, C16, C21 47nF ceramic C12, C19 47mF/16V electrolytic C13, C14 10nF ceramic C15 100nF polyester C17 10mF/16V electrolytic C18 2,2mF/16V electrolytic C20 470mF/16V electrolytic D1 AA119, AA117 (g ermanium diode) Q1, Q2 BF241 (amplifiers of intermediary frequency) U1 SO42P (mixed and local oscillator) U2 LM386 (amplifier A.F.) Y1, Y2 Crystals hails. (You can you put the so much, those who also channels that you want you touch). See here. MF1 Medium frequency 455KHz, core yellow. * MF...

Schematic  is suitable for use in radio tuner or FM radio receiver when it is assembled and ready for use. Where if the low gear power radio receiver, with the aid of power amplifier is less powerfull voice / hard to better and just right. For use hios  speakers , use a low-power , because power amplifier has only the power output of 2 X 5 Watt stereo power amplifeir with impedance of 4 Ohm. Working on a minimum voltage of 4.5 Volts and maximum of 16Volt. Use the correct voltage supply - really have been filtered out in order to improve the performance of these power amplifiers. Component Description : Resistor R1________180R R2________180R R3________18K R4________18K Capacitor C1________47uF C2________4.7uF C4________100uF C5________100uF C6________47uF C7________4.7uF C8________47uF C9________100uF C10_______100uF C11_______1000uF C12_______1000uF C13_______100pF C14_______100pF C15_______68n C16_______68n IC IC1_______TA7215P