In order to ensure A phase and B phase circuits are symmetric, digital potentiometer X9C503 with exterior pressed key in the feedback amplification circuit is designed.
在反馈放大电路设计时，采用数字电位器X9C503与外部按键配合，达到了A、B两相电路的对称性。
2
The TTL video signal from PC is converted into R, G, B video signals through PC video interface circuit.
来自个人计算机（PC）的TTL视频信号由PC视频接口电路转换成R、G、B视频信号。
3
The row pulse signal forming circuit generates a row pulse signal B.