电压减法电路

就是一般的加法器接法的不同，简单的方法是将一路用反相器反相后，两路相加。
The next generation keyboard, future keyboard!
challenge and subverting the global computer keyboard, keyboard music instruments in 25 years ago，
The pioneer of the Chinese people firstly entered this area. who sent it into the modern house of CEO of Microsoft?
To challenge AT&T of the United States by improving communication deficiencies
Improving communication deficiencies, Chinese people challenge AT&T of the United States.