08-05-2012, 01:23 PM
Wireless Music transmission and reception by IR communication
WIRELESS MUSIC TX & RX BY IR COMM............docx (Size: 643.19 KB / Downloads: 129)
. INTRODUCTION:
Using this circuit, audio musical notes can be generated and can be heard up to a distance of 10
meters. The receiver can be placed at a maximum distance of 1 meter from the transmitter
without any considerable noise interference. The circuits of transmitter and receiver are quite
simple and can be placed and carried any where easily. The small apparatus provided with the
infrared communication function is in many cases operated by a battery incorporated inside so
that it is convenient when a user carries it during movement, and it is preferable that power
consumption be minimized also to lengthen the continuous operation possible time of IR
emission is optimized. We don’t make use of any of modulation techniques when working with
IR rays. Hence there is no necessity of carrier generation. This makes the transmitter and
receiver designs much simpler. However the communication distance can be improved by using
Far IR LEDs. The range of communication can be increased to about 250 meters by using far IR
LEDs. In the apparatus provided with a conventional infrared communication function,however,
the infrared light with a constant intensity is constantly radiated regardless of the
communication distance. This project emphasizes the way by which music is generated and
driven by IR rays and gives an explanation to the one of the methods of receiving IR rays
without considerable noise interference.
OPERATION:
The circuit can be divided into two parts: IR music transmitter and receiver. The IR music
transmitter works off a 9V battery, while the IR music receiver works off regulated 9V to 12V.
Fig. 1 shows the circuit of the IR music transmitter. It uses popular melody generator IC UM66
(IC1) that can continuously generate musical tones. The output of IC1 is fed to the IR driver
stage (built across the transistors T1 and T2) to get the maximum range. Here the red LED
(LED1) flickers according to the musical tones generated by UM66 IC, indicating modulation.
IR LED2 and LED3 are infrared transmitting LEDs. For maximum sound transmission these
should be oriented towards IR phototransistor L14F1 (T3). The IR music receiver uses popular
op- amp IC μA741 and audio-frequency amplifier IC LM386 along with phototransistor L14F1
and some discrete components (Fig. 2). The melody generated by IC UM66 is transmitted
through IR LEDs, received by phototransistor T3 and fed to pin 2 of IC μA741 (IC2). Its gain
can be varied using potential meter VR1. The output of IC μA741 is fed to IC LM386 (IC3) via
capacitor C5 and potential meter VR2.The melody produced is heard through the receiver’s
loudspeaker. Potential meter VR2 is used to control the volume of loudspeaker LS1 (8-ohm,
1W). Switching off the power supply stops melody generation.
.POWER SUPPLY:
The input to the circuit is applied from the regulated power supply. The a.c. input i.e., 230V from the mains supply is step down by the transformer to 12V and is fed to a rectifier. The output obtained from the rectifier is a pulsating d.c voltage. So in order to get a pure d.c voltage, the output voltage from the rectifier is fed to a filter to remove any a.c components present even after rectification. Now, this voltage is given to a voltage regulator to obtain a pure constant dc voltage.
WIRELESS MUSIC TX & RX BY IR COMM............docx (Size: 643.19 KB / Downloads: 129)
. INTRODUCTION:
Using this circuit, audio musical notes can be generated and can be heard up to a distance of 10
meters. The receiver can be placed at a maximum distance of 1 meter from the transmitter
without any considerable noise interference. The circuits of transmitter and receiver are quite
simple and can be placed and carried any where easily. The small apparatus provided with the
infrared communication function is in many cases operated by a battery incorporated inside so
that it is convenient when a user carries it during movement, and it is preferable that power
consumption be minimized also to lengthen the continuous operation possible time of IR
emission is optimized. We don’t make use of any of modulation techniques when working with
IR rays. Hence there is no necessity of carrier generation. This makes the transmitter and
receiver designs much simpler. However the communication distance can be improved by using
Far IR LEDs. The range of communication can be increased to about 250 meters by using far IR
LEDs. In the apparatus provided with a conventional infrared communication function,however,
the infrared light with a constant intensity is constantly radiated regardless of the
communication distance. This project emphasizes the way by which music is generated and
driven by IR rays and gives an explanation to the one of the methods of receiving IR rays
without considerable noise interference.
OPERATION:
The circuit can be divided into two parts: IR music transmitter and receiver. The IR music
transmitter works off a 9V battery, while the IR music receiver works off regulated 9V to 12V.
Fig. 1 shows the circuit of the IR music transmitter. It uses popular melody generator IC UM66
(IC1) that can continuously generate musical tones. The output of IC1 is fed to the IR driver
stage (built across the transistors T1 and T2) to get the maximum range. Here the red LED
(LED1) flickers according to the musical tones generated by UM66 IC, indicating modulation.
IR LED2 and LED3 are infrared transmitting LEDs. For maximum sound transmission these
should be oriented towards IR phototransistor L14F1 (T3). The IR music receiver uses popular
op- amp IC μA741 and audio-frequency amplifier IC LM386 along with phototransistor L14F1
and some discrete components (Fig. 2). The melody generated by IC UM66 is transmitted
through IR LEDs, received by phototransistor T3 and fed to pin 2 of IC μA741 (IC2). Its gain
can be varied using potential meter VR1. The output of IC μA741 is fed to IC LM386 (IC3) via
capacitor C5 and potential meter VR2.The melody produced is heard through the receiver’s
loudspeaker. Potential meter VR2 is used to control the volume of loudspeaker LS1 (8-ohm,
1W). Switching off the power supply stops melody generation.
.POWER SUPPLY:
The input to the circuit is applied from the regulated power supply. The a.c. input i.e., 230V from the mains supply is step down by the transformer to 12V and is fed to a rectifier. The output obtained from the rectifier is a pulsating d.c voltage. So in order to get a pure d.c voltage, the output voltage from the rectifier is fed to a filter to remove any a.c components present even after rectification. Now, this voltage is given to a voltage regulator to obtain a pure constant dc voltage.