常规的移位寄存器,例如74HC595,需要数据信号、时钟信号和选通逻辑信号。图1所示电路仅需两个逻辑信号来对移位寄存器进行隔离和控制。对于传输的每一个二进制位数据,两个光电耦合器总有一个会接收到一个短的驱动脉冲:一个光电耦合器响应所传输的高位,另一个响应低 Conventional shift registers, such as the 74HC595, require data signals, clock signals, and strobe logic signals. The circuit shown in Figure 1 requires only two logic signals to isolate and control the shift register. For each bit of data transmitted, one of the two optocouplers will always receive a short drive pulse: one photocoupler responds to the transmitted high bit and the other responds low