Circuit Wiring Solution: fm

Showing posts with label fm. Show all posts

Tuesday, November 11, 2014

FM booster schematic circuit with explanation

A low-cost circuit of an FM booster that can be used to listen programs from distant FM stations clearly. The circuit comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570 ( C2570).
This FM booster circuit is constructed using few common components ( not require some special components ) and provide a very good gain .
To calibrate this circuit you need to adjust input/output trimmers (VC1/VC2) for maximum gain.
Input coil L1 consists of four turns of 20SWG enamelled copper wire (slightly space wound) over 5mm diameter former.

It is tapped at the first turn from ground lead side. Coil L2 is similar to L1, but has only three turns.
Both of the trimmers are 22pF value .This FM radio signal booster needs to be powered by a 12 volts DC power supply

more at: electroniq.net/radio-frequency/fm-booster-schematic-circuit.html

Friday, October 31, 2014

Microphone FM Transmitter Wireless Two Transistors Circuit

Please be warned if operating this circuit might violate the regulation of your country, because this FM transmitter circuit radiate strong radio frequency to the environment. This wireless microphone is very sensitive, pick up every sound in the 20m radius, and transmit the radio signal up to 2 kilometers in open air. The first transistor (Q1) is the pre-amplifier for the microphone, and you can ommit this circuit if you don’t want to transmit the sound picked up by the mic, for example you can can connect your mp3 player directly to C1. The core of this FM transmitter circuit is Q2, a modified Collpits oscillator that the frequency is determined by L1, C4, C6, and the transistor’s internal base-emitter capacitance. The antenna use 1/16 wave length to compromize between the efficiency and the size.

If you want the microphone to be less sensitive, you can replace the R1 by a higher resistor, try 10k or 22k, and this might overcome the feedback problem if you use this wireless microphone FM transmitter for a public address system.

Wednesday, October 29, 2014

FM 250mW transmitter electronic Circuit diagram

A very simple FM transmitter electronic project can be designed using this circuit diagram . This FM transmitter electronic project works in FM band and it has a transmission power around 250mW ( thing that make it to work at above hundred meters ) . This FM transmitter electronic circuit is very simple and is based on some common transistors and electronic parts .
T1 transistor can be a BC107, BC171 or equivalent , and is used as an small audio preamplifier that amplify the audio signal from the microphone . Adjusting the R2 variable resistor, audio signal level from the input ( microphone ) can be adjusted until will be delivered to the T1 preamplifier (an over amplified signal applied to T1 can produce an overmodulation) . From T1 , signal is delivered to T2 which form an Hartley oscillator (frequency of this oscillator depends of C8,C9 and L1) .

fm 250mw transmitter electronic circuit project with explanation

The transmitter frequency oscillator works in FM band 87.5-108 MHz and can be set , adjusting C8 capacitor and L1 coil . L1 coil must have four turnings on a 0.8-1 mm cylinder support with a 6 mm diameter (space between each wire must be around 1 mm ) .
Antenna used for this project can be a simple telescopic antenna or a 60-70 mm Cu wire .
This electronic project can be powered from a wide range input voltage from 9 to 12 volts Dc ( but can be used even a 18 volts DC .

Wednesday, October 8, 2014

New FM Stereo Transmitter BH1415F

BH1415F can be supplied with 6 - 15V voltage, consumes only around 25mA while providing very sound quality and improved 40dB channel separation. BH1415 is only available in SOP22 IC case and this may be an inconvenience for some folks. On the other hand, because the chip is smaller than regular DIP-based ICs it is possible to fit the entire stereo coder on a small PCB.

Sunday, September 7, 2014

Tracking FM Transmitter Schematics

FM tracer was prepared using the LM3909 IC and some supporting components. 1.5V FM trackers This will provide an indicator of revenue sources by providing a signal emitted by the LED. FM tracking uses a source voltage of the battery cell and fruit consumption current is 3.7 mA.

After completion of assembling Tracker FM 1.5V, then the next step is setting the operating frequency of the FM tracker is, for convenience we can use the FM receiver and adjust the working frequency FM 1.5V Tracking (tracking transmitter) by regulating C3.

Have been obtained if the working frequency Tracking FM 1.5V (tracking transmitter) then the corresponding LED will light emitted by the transmitter information such as sound through an FM receiver is terdengan. 1.5V FM tracker (tracking transmitter) can use a regular 12-inch antenna. Playing and learning electronics that will be happy,

1.5 Volt Tracking FM circuit (Tracking Transmitter)

Circuit Description 1.5 Volt Tracking FM (Tracking Transmitter)

For stability, use a NPO types for C2 & C4.
Tolerance for R1 should be 1 or 2%.
Frequency range is usually 87-109Mhz FM.
Email wire used in wire coil is made of hookup 22 ga, like the solid Bell phone wire.

Tuesday, September 2, 2014

FM transmitter using UPC1651

Here is the schema diagram of an FM transmitter using the IC UPC1651. UPC1651 is a wide band UHF Silicon MMIC amplifier. The IC has a broad frequency response to 1200MHz and power gain up to 19dB.The IC can be operated from 5V DC.

The audio signals picked by the microphone are fed to the input pin (pin2) of the IC via capacitor C1. C1 acts as a noise filter. The modulated FM signal will be available at the output pin (pin4) of the IC. Inductor L1 and capacitor C3 forms the necessary LC schema for creating the oscillations. Frequency of the transmitter can be varied by adjusting the capacitor C3.

Notes. * The schema can be assembled on a Vero board. * Inductor L1 can be made by making 5 turns of 26SWG enameled copper wire on a 4mm diameter plastic former. * A ¾ meter insulated copper wire can be used as the antenna. * Do not give more than 6V to the IC. * Mic M1 can be a condenser microphone.

Sunday, August 31, 2014

Four Stage FM Transmitter

This FM transmitter schema uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built around transistor 2N3866 (T4). A condenser microphone is connected at the input of the oscillator.

Four-Stage FM Transmitter Circuits diagram :

Four-Stage FM Transmitter Circuits Diagram

Working of the schema is simple. When you speak near the microphone, frequency-modulated signals are obtained at the collector of oscillator transistor T1. The FM signals are amplified by the VHF preamplifier and the pre-driver stage. You can also use transistor 2N5109 in place of 2N2219. The preamplifier is a tuned class-A RF amplifier and the driver is a class-C amplifier. Signals are finally fed to the class-C RF power amplifier, which delivers RF power to a 50-ohm horizontal dipole or ground plane antenna. Use a heat-sink with transistor 2N3866 for heat dissipation. Carefully adjust trimmer VC1 connected across L1 to generate frequency within 88-108 MHz. Also adjust trimmers VC2 through VC7 to get maximum output at maximum range.

Regulator IC 78C09 provides stable 9V supply to the oscillator, so variation in the supply voltage will not affect the frequency generated. You can also use a 12V battery to power the schema.

Assemble the schema on a general-purpose PCB. Install the antenna properly for maximum range. Coils L1 through L5 are made with 20 SWG copper-enamelled wire wound over air-cores having 8mm diameter. They have 4, 6, 6, 5 and 7 turns of wire, respectively.

EFY note. This transmitter is meant only for educational purposes. use of this transmitter with outdoor antenna is illegal in most parts of the world. The author and EFY will not be responsible for any misuse of this transmitter.

Author : Pradee G. - Copyright : EFY

Thursday, August 28, 2014

Simple Sub carrier Adapter For Fm Tuners Wiring diagram Schematic

Simple Sub carrier Adapter For Fm Tuners Circuit Diagram. In this schema Op amp Ul and its associated components comprise the 67-kHz bandpass filter. A twin-T network, comprised of four 1100-12 resistors and four 0.0022- capacitors, is connected in the feedback network of the op amp.

Sub carrier Adapter For Fm Tuners Circuit Diagram

That gives some gain at 67 kHz and heavy attenuation for frequencies above and below that frequency. An additional passive filter at the input to the twin-T network (containing a 220-pF capacitor and a 10,000- resistor) provides some additional roll-off for frequencies below 67 kHz. In practice, the bandpass-filter action covers a frequency range of about 10 kHz above and below the 67-kHz center frequency. Resistor R18 sets the gain of the bandpass-filter stage. Integrated-schema U2 is a National LM565 phase-locked loop that modulates the 67-kHz fre-quency-modulated (FM) signal from Ul.

The LM565 PLL consists of a voltage- controlled oscillator (VCO) set to 67 kHz, and a comparator that compares the incoming frequency-modulated 67-kHz signal at pin 2 with the VCO signal that is fed into pin 5. The output of the comparator represents the phase difference between the incoming signal and the VCO signal. Therefore, the output is the audio modulated by the subcarrier. A treble deemphasis of 150 is provided by a 0.033- capacitor (at pin 7). The free-miming VCO frequency is determined by the 0.001- capacitor at pin 9 and by the resistance between the positive rail and pin 8 (100 in series with R19). Variable-resistor R19 adjusts the oscillator frequency (also known as the center frequency`) so that the incoming signal is within the lock range of the PLL.

Wednesday, August 27, 2014

Using 555 as FM transmitter Wiring diagram Schematic

The integrated schema 555 has no limits, this FM transmitter schema, the IC 555 is designed as an stable multivibrator as usual. But the tension control pin is used to connect a piezoelectric element instead of the capacitor disk. The piezoelectric element generates a voltage and the output pin is connected to an antenna wire 30 inches for the transmission of signals.Just tap the piezo element and you can hear the sound on an FM radio station. The range is very short.

Using 555 as FM transmitter Circuit Diagram

Tuesday, August 26, 2014

Build a FM Booster Wiring diagram Schematic

A low-cost schema of an FM booster that can be used to listen programs from distant FM stations clearly. The schema comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570 ( C2570). this FM booster schema is constructed using few common components( not require some special components ) and provide a very good gain .to calibrate this schema you need to adjust input/output trimmers (VC1/VC2) for maximum gain.

FM Booster Circuit Diagram Circuit Diagram

Input coil L1 consists of four turns of 20SWG enamelled copper wire (slightly space wound) over 5mm diameter former. It is tapped at the first turn from ground lead side. Coil L2 is similar to L1, but has only three turns. Both of the trimmers are 22pF value. This FM radio signal booster needs to be powered by a 12 volts DC power supply .

Wednesday, August 20, 2014

AN7415 FM Stereo Demodulator

The circuit shown below is of a PLL FM stereo demodulator designed Depending the AN7415. C1 is the input coupling capacitor Which blocks any DC voltage present at the multiplexed input signal. LED D1 is an indicator LED and R1 is its current limiting resistor. C4 and C5 seem to be the DC decoupling capacitors in to the left and right output channels.

C2 and C3 to be the noise bypass capacitors to the left and right output channels. POT R2 can be used for adjusting the channel separation. Resistor R5 and capacitors C7 and C8 forms a low-pass filter network in to the internal DC amplifier circuitry. C10 is extremely a filter capacitor in to the IC’s internal Schmitt trigger amplifier circuitry.

C9 is extremely a ripple filter capacitor in to the voltage stabilizer circuit inside the AN7415. Resistor R3, POT R4 and Capacitor C6 sets the time constant of these internal VCO circuit. Hence POT R4 can be used for adjusting the VCO frequency. A 19KHz frequency check signal is available at the PIN 12 of these IC. Switch S1 can be used for enabling and disabling forced mono function.

Tuesday, August 19, 2014

Mini FM Transmitter Wiring diagram Schematic

This is a some what powerful transmitter.Here I have used famous Transistor 2N2222.This schema operates with 3V power supply.To make L1 wind 5 turns of 24AWG wire on a 1cm plastic former.