This article refers to the address: http:// BH501 is a keyboard ASIC integrated with BH200 series , which can form the sound source, envelope circuit and sustain control circuit of the keyboard. This circuit is typically used for 73 keys and extended application up to 88 keys. BH501 is manufactured in CMOS process, mostly used in Medium and high-end electronic piano. Its typical application is shown in the figure. The terminal, each button switch and a 4.7UF sustain capacitor; 3 feet for the sustain control terminal. Bridge Load Cells,Half Bridge Load Cell,Dual Bridge Load Cells,Full Bridge Load Cell Xiaogan Yueneng Electronic Technology Co., Ltd. , https://www.xyeloadcell.com