Solar cells; electric current sensor; [ compact disc players; record players; portable audio players; loud speakers; amplifiers; amplifiers for stereo system, and parts thereof; amplifiers for surround sound, and parts thereof; amplifiers for headphones; multichannel amplifiers; amplifiers with noise reduction circuits for sound signal; ] battery charger for electric vehicle, namely, battery car, hybrid car and power-assisted bicycle; laboratory robots; security surveillance robots; integrate...