FM wireless Mike is a small electronic project based on a radio transmitter. It is a wonderful idea to make a wacky talky through which you can talk to your friend, next door. Just speak or play into the microphone and you ’ll broadcast to an FM receiver at distances up to 50 feet (maybe 100 feet if the wind is right). Use a standard FM radio to r
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eceive the sound. Microphone Preamplifier is a simple audio amplifier. Transistor Q1 is operated in Voltage Divider Mode. We use a dynamic microphone in the amplifier. The small alternating current produced in the microphone is amplified and fed in to the FM transmitter. FM transmitter is a tuned collector radio frequency oscillator. The coil and trimmer is in parallel tank circuit. We specify the value of trimmer and size of the coil such that the resonant frequency will be near 88-108 MHz (in the FM radio Band). The oscillator oscillates with a constant resonant frequency and we can change the operating frequency by changing the trimmer capacitance. This frequency is the center frequency of the FM. If we want the FM as a modulation we have to apply the modulating signal (audio signal from amplifier) to the base of the transistor of the oscillator. We all know the base-emitter junction acts like a diode. If we apply the signal the voltage across the junction will change and this particular transistor have some property of changing base capacitance according to the applied input voltage. Thus we change the capacitance which is in series with the resonant tank circuit causing a change in operating frequency. This is actually the FM modulation. Now the modulated signal will be transmitted via a small radio antenna.
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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