Here is a simple IR headphone circuit that is suitable for listening to TV or radio with out disturbing others. For beginners the IR headset is a better option than FM head sets because they often produce desirable sound quality with out tuning as well as difficult impedance matching that is often done in radio circuits which is difficult for begi
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nners. The audio signal is coupled to the base of T1 (BC547) by an audio transformer. The T1 pre amplifies the signal. The transistor T2 (BD 140) drives the IR LED`s which transmit the sound as IR beams. The red LED provides fixed bias for theT2 as well as a power on indication. The transmitter has a 5m range under normal conditions. A 9V battery can be used to power the transmitter. The photo transistor T3 receives the IR signals. The collector of IR is connected to base of T4(BC548) which amplifies the signal together with T5 (BC549)to regain the audio signal transmitted. The transistor T6 drives the headphone to reproduce the sound. The receiver can be powered by using a 9V battery. The audio transformer can be easily obtained from a old transistor radio. It should be connected with the low impedance winding (thicker) to the audio input (TV or radio) side.
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....
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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....
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