This infrared transmitter use PWM (pulse width modulation). The transmitter is equiped with LM567, tone decoder circuit. Audio signal ( at least 50mVvv ) is amplified with T1 and then it is used to ...

This infrared transmitter can be used with this infrared receiver. This transmitter uses. The modulated signal is produced by comparison of an audio signal with a triangle signal of high frequency ...

Using this circuit, audio musical notes can be generated and heard up to a distance of 10 metres. The circuit can be divided into two parts: IR music transmitter and receiver. The IR music transmitter ...