数字抢答器由主体电路与扩展电路组成。优先编码电路、锁存器、译码电路将参赛队的输入信号在显示器上输出；用控制电路和主持人开关启动报警电路，以上两部分组成主体电路。通过定时电路和译码电路将秒脉冲产生的信号在显示器上输出实现计时功能，构成扩展电路。经过布线、焊接、调试等工作后数字抢答器成形。-Answer the number of circuits is controlled by the main circuit and expansion. Priority encoder circuit, latch, decoder circuit will be teams of the input signal in the display output　with control circuitry and the host switch alarm circuits, and above the main circuit composed of two parts. Through the timing circuit and decoding circuit to generate pulse signals in the display output timing functions, constitute the expansion of the circuit. After wiring, welding, testing, etc. Answer the number of devices after the forming.