Tag Archives: transmitter

Simple FM Radio


by electronics-diy.com:

This is one of my favorite radio builds just because of how simple it is and how well it is able to pick up a lot of FM radio stations. I have browsed the world in search of a one transistor FM receiver. I have seen a couple but they were always attached to some sort of added device, such as another IC or another transistor for amplification in the receiver itself. Through my continued quest of searching for that too good to be true one transistor, I happened to run across a super-regenerative receiver, by Charles Kitchin, famous for his vast knowledge of regenerative designs. I printed out the schematic and made it. It turned out extremely well.

Simple FM Radio – [Link]

Simple Infrared Barrier


by Maurizio @ dev.emcelettronica.com:

Although a remote control is not so difficult to design and build, there is an even simpler option: the IR barrier. This consists of a constant IR signal permanently going from an emitter to a receiver, both of them being in two different places (a few meters apart). When an obstacle comes in between the emitter and the receiver, the IR signal is blocked and the receiver senses that it is missing, flagging the event in an appropriate manner (figure 1).

The principle of operation is simple enough, and with most components taken off the shelf, it is easy to design the schematic. The IR element in the emitter is a simple IR LED. This behaves absolutely like any other LED, with the sole exception that it emits light in the infrared spectrum. The emitted light is thus invisible to human eye, but it is meant to excite the infrared receiving element on the other side of the barrier. One important element of this LED is the wavelength of the emitted light, of which we already know that is in the infrared spectrum.

Simple Infrared Barrier – [Link]

Wireless Transmitter System

This wireless project is a power transmission system, it works on the principle of magnetic induction. This Wireless Charging system works as the digital switched mode power supply with the transformer, which is separated into two parts: The transformer primary coil is on the transmitter, working as the transmitter coil, and the transformer secondary coil is on the receiver side as the receiver coil. This system works based on magnetic induction, the better coupling between the transmitter coil and receiver coil gain, the better system efficiency. So the receiver coil should be closely and center aligned with the transmitter coil as possible. After the receiver coil receives the power from the transmitter coil by magnetic field, it regulates the received voltage to power the load, and send its operational information to transmitter according to specific protocol by the communication link. Then the system can achieve the closed-loop control, and power the load stably and wirelessly. Continue reading Wireless Transmitter System

World’s first fully digital radio transmitter built purely from microprocessor technology


by Colin Jeffrey @ gizmag.com:

For the first time in history, a prototype radio has been created that is claimed to be completely digital, generating high-frequency radio waves purely through the use of integrated circuits and a set of patented algorithms without using conventional analog radio circuits in any way whatsoever. This breakthrough technology promises to vastly improve the wireless communications capabilities of everything from 5G mobile technology to the multitude devices aimed at supporting the Internet of Things (IoT).

World’s first fully digital radio transmitter built purely from microprocessor technology – [Link]

Wireless IR Headphone Transmitter


Infrared headphones can be used for listening to music or television cordlessly. The headphones utilize a transmitter that connects with audio cables to the audio source, such as a home entertainment center. The transmitter utilizes light-emitting diodes (LEDs) to direct a focused beam of invisible pulsating light towards a receiver built into the headphone set. The pulsations act as ON/OFF signals that are translated digitally by the receiver into audible sound waves. Most infrared headphones have an effective range of about 30 feet (~10 meters) or less, and require a clear line of sight between transmitter and receiver.

Sound comes out of the stereo system through audio cables and into an infrared transmitter. The transmitter turns the sound into a series of pulses. The pulses work like bits in a computer, digitally capturing the sound information. These pulses are then sent to an infrared LED.

For the transmitter side, an audio input from PL1 frequency modulates the VCO section of a HEF4046BT PLL chip. The VCO output drives Q1, a switching transistor. Q1 drives two IR LEDs. The signal produced is around 100 kHz, FM carrier VCO sensitivity is around 7.5 kHz/V.

Wireless IR Headphone Transmitter – [Link]

Raspberry Pirate Radio


by Sam Freeman and Wynter Woods @ makezine.com:

This simple hack turns your Raspberry Pi into a powerful FM transmitter! It has enough range to cover your home, DIY drive-in movie, a high school ball game, or even a bike parade (depending on the stragglers).

PiFM software not only boldly enhances the capability of your Pi, but does so with nothing more than a single length of wire. This hack starts with the absolute minimum you need to run a Raspberry Pi — an SD card, a power source, and the board itself — and adds one piece of wire. It’s the coolest Pi device we’ve ever seen with so few materials.

Raspberry Pirate Radio – [Link]

Mini FM transmitter


electronics-diy shows you how to easily make a mini FM transmitter:

It transmits FM waves so you could easily receive the signals on your mobile phone, radios, etc. As the name and the picture indicates it is very small and is approximately the size of a 9v battery clip. With this FM transmitter you could start your own mini FM station. The circuit uses BC547 transistor to amplify the signal and then frequency modulate it. It uses “frequency modulation