You can use this simple Amplifier to hear Music from Mobile Phone or MP3 player. It gives very clear sound through two 8 ohm speakers. It uses two identical circuits for Stereo operation. IC LM386 is the low power Amplifier IC ideal for battery operation. The output from Mobile phone is Pre amplified so that it can be provided to the input of the Amplifier using a Stereo jack. The filter circuit comprising resistors and capacitors at the front end filters the audio entering into the amplifier to give clear sound.
You can hear a local AM station clearly with this IC radio. It is tuning free so only the strongest nearby station will be available. Only a few components are necessary to build this Matchbox size radio and can be assembled quickly on a common PCB. No coil, No Gang, No professional touch. But still it is a Radio. See the trick to use the Gain pins of an amplifier IC as Signal receiver.
Continue reading “Tuning free AM Receiver. Design Trick 12”
You can use this Mini amplifier to hear music from Mobile phone or Laptop. The speaker of Mobile phone and Laptop is too small and the output voice is sharp with high tone which is not pleasant to hear music for long time. This circuit will solve the problem. It can be connected to the earphone socket of Mobile phone or Laptop. It is too small and portable. IC LM386 is used in the circuit which is a low voltage audio amplifier IC and its gain is internally set to 20.
Continue reading “Mobile phone Amplifier. Design Trick 7”