Garage Door Opener Transmitter

This electronic circuit is the newer and revised version of the garage door opener transmitter. The transmitter is a PIC based on 40 MHz Microchip’s 16F630 microcontroller. A 10 switch DIP-switch is used for setting the code. To save space, we used a different HF output coil. Schematic , PCB files and hex code are available.Download Documentation...

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VHF/UHF TV Modulator

The electronic circuit is a TV modulator that is really no more than a transmitter. It is a very small transmitter, admittedly, but none the less that is what it is. What does a modulator actually do? In general -and this design is no exception to the rule - it is a simple oscillator that generates a frequency somewhere in the VHF or UHF...

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Stereo FM Transmitter Based BA1404 Chips

This electronic circuit design is a stereo FM transmitter that improves sound quality, has very good frequency stability, maximizes transmitter's range, and is fairly simple for everyone to build. We are happy to announce that this goal and expectations have been met and even exceeded.The transmitter can work from a single 1.5V cell battery...

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Stereo FM Transmitter Based BH1417 Chips

This electronic circuit is a latest BH1417 FM Transmitter design from RHOM that includes a lot of features in one small package. It comes with pre-emphasis, limiter so that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass filter that blocks any audio signals above 15KHz to prevent any...

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Transistor Schmitt Trigger Oscillator

The Schmitt Trigger oscillator below employs 3 transistors, 6 resistors and a capacitor to generate a square waveform. Pulse waveforms can be generated with an additional diode and resistor (R6). Q1 and Q2 are connected with a common emitter resistor (R1) so that the conduction of one transistor causes the other to turn off. Q3 is controlled...

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FM Transmitter with 2 Transistor

This FM ransmitter circuits may be tuned to operated over the range 88-108 MHz. Although only low power this circuit can be transmitted with a range of 20 or 30 metres. It's suitable for use as wireless microphone.This circuit used a pair of BC548 transistors. Although not strictly RF transistors, they still give good results. Use an ECM...

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Arduino + Laser Pointer + Servos = Homemade Laser Cannon

After discovering how ridiculously easy it was to control a servo motor from the Arduino, I wondered what 2 servos and a laser pointer could do...Long story short, I now have a computer controlled laser cannon muhahha!The whole thing is controlled via serial commands, which let me:Control pitch (Y) and yaw (X)Turn the laser on and offMake...

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88-108 MHz Voltage Controlled Oscilator for PLL Controller

This Circuit will explain the PLL unit and the VCO (Voltage Controlled Oscillator) which will create the FM modulated RF signal up to 400mW. the schematic to follow my function description. The main oscillator is based around the transistor Q1. This oscillator is called Colpitts oscillator and it is voltage controlled to achieve FM frequency...

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88-108 MHz PLL Controller for FM Transmitter

This circuit will explain the PLL controller unit for the FM transmitter. It is very important since the transmitter frequency is digitally controlled and thereby very stable. The heart of this unit is a PIC processor called PIC16F870, a 2 x 16 char display and four buttons.Circuit SchematicYou will also find a 2 line 16 char display based...

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Arduino Based Data Logger

Well I thought it was about time I actually finished a project I started (enough to boast about online anyway). I recently bought myself an Arduino and just about every attachment under the sun, and have really been stumped for interesting projects to do with it.I decided to build myself a makeshift data logger to sample the temperature and...

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Ring Circular Polarized Antenna for 88-108 MHz

This simple antenna called Ring Circular Polarized Antenna. You should construct this antenna with .5 inch copper. With a little experiment I did, antenna can be tuned in 88-108 MHz FM frequency range with only changing the vertical elements. The secret is a ratio of vertical and horizontal dimensions.In FM transmitter you need signal transmitted...

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Low Power VHF TV Transmitter

One of the most useful gadgets a video enthusiast can have is a low-power TV Transmitter. Such a device can transmit a signal from a VCR to any TV in a home or backyard. Imagine the convenience of being able to sit by the pool watching your favorite movie on a portable with a tape or laserdisc playing indoors. You could even retransmit cable...

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80mW FM Transmitter with Dipole Antenna

This electronic circuit is a fm transmitter circuit that suitable for beginners for stereo encoder testing. Provided the input stage is designed to accommodate line input levels i.e. approx. 2Vrms into 50kOhm. The transmitter output power is approx. 80mW, which is sufficient to cover an area of about one hundred meters.The RF portion consists...

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FM Stereo Encoder for Beginner

This circuit is a simple fm stereo encoder. A method commonly used in (double side-band suppressed carrier) DSB-SC modulation to provide synchronisation between modulator and demodulator is to transmit a sinusoidal tone (pilot tone) whose frequency and phase are related to the carrier frequency. This tone is positioned at 19 kHz, outside...

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Simple FM transmitter with a Single Transistor

Mini FM transmitters take place as one of the standard circuit types in an amateur electronics fan's beginning steps. When done right, they provide very clear wireless sound transmission through an ordinary FM radio over a remarkable distance. I've seen lots of designs through the years, some of them were so simple, some of them were powerful,...

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Broadband RF Amplifier For TV Transmitter 5W

This Broadband RF amplifier is for driving small UHF TV transmitters, with gain is 7dB and can amplify a signal between 470-860 MHz. Drive input the circuit with 1 to 1,5 Watts signal. Better use double layer PCB with the second layer connected to earth.Use a stabilized power supply 24 volts and at least 5 Amps. The transistor case is the...

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RF Power Amplifer for UHF TV Transmitter #2

from RF Power Amplifer for UHF TV Transmitter #1MECHANICAL MACHINING OF THE HEATSINKThe raised edges at the top side of the heatsink have been removed because the printed circuit board has a width of 113 mm (see Fig.3). To fit the heatsink to the printed-circuit board the following machinings have been carried out:Rectangular holes of 2.8...

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RF Power Amplifer for UHF TV Transmitter #1

INTRODUCTIONThe construction taken from the application report NCO8101 two amplifiers for band 4/5 with BLV57 transistors have been described. Reactions on this report proved the necessity to give more information about the construction of these amplifiers. This construction has been based on a heatsink with a printed-circuit board at the...

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Broadband RF Amplifier For TV Transmitter 14W #2

BIAS CIRCUITFrom Broadband RF Amplifier For TV Transmitter 14W #1Below is the RF power amplifier's components part list and bias circuit for supply feeding.C1, C2, C4, C5, C6 = 1nF LCC Chip + 10nF LCC ChipC3 = 100µF SpragueC7 = 10µF SpragueD1 = 1N 4001L1, L2 = 5 Turns , Diameter 0.5 mm, W Diameter 3mmP1 = 1k.R1 = 56 ohm/ 1/2WR2 = 5600 ohm,...

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Broadband RF Amplifier For TV Transmitter 14W #1

This RF power amplifier works in frequency 470 - 860 MHz UHF Band IV and V with power out 14 Watts with input power 1.5 Watts. The power amplifier is suitable for amplifying rf signal your tv transmitter with 0.5 - 2 watts power output.SchematicRF power amplifier circuit is taken from Philips transistor application note, as you can see below.Part...

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Broadband UHF Power Amplifier For TV Transposers 3W

A Broadband RF Amplifier design is presented, suitable for application in TV transposers, operating in UHF band IV and V(470 - 860) MHz, with simple printed circuit board.The Rf power amplifier design is based on a BLW898 bipolar transistor. Typical results at the recommended class-A biaspoint (25 V/1.1 A) for the total module include a 3-tone...

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Broadband RF Amplifier For TV Transmitter with BLV859

A broadband rf amplifier design is presented, suitable for application in TV transposers operating in band IV and V (470 to 860 MHz). The design is based on two BLV859 bipolar transistors combined with quadrature hybrids. Typical results at the recommended class-A bias point (25.5 V/9.1 A) for the total module include 40 W peak sync output...

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Broadband RF Amplifier 100W for TV Transmitter

The TV rf power amplifier has been tuned under class-A small-signal conditions and characterised under large signal class-AB conditions from band IV - V in UHF. The amplifiers circuit of the input and output matching networks contain mixed microstrip-lumped elements networks to transform the terminal impedance levels to approx. 25 W balanced.The...

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Broadband RF Amplifier 470-860 MHz with BLW32-33

This Broadband RF Amplifier for 470-860 MHz taken from Philips Aplication Note (AN_BLW32_33). Please download file in PDF format.The broadband rf amplifier for TV Transposer band IV/V designed with transistor BLW32 and BLW33. In this case, my RF Amplifier design replaced them with 2 pieces BLW34 have good result.Download combine two BLW34...

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