In order to avoiding the phenomena of false alarm and missed alarm of in frame synchronization circuit by the use of tri-state logic it designs frame check / protection circuit to assure the reliability of synchronous circuit .

为避免帧同步电路的虚警、漏警现象，采用 三 态 逻辑判断方法设计了帧同步校验/保护电路来确保帧同步电路的可靠性。

A kind of function fine tri-state logic indicating circuit

一种功能优良的 三 态 逻辑指示电路

This circuit may make a tri-state logic pen or is installed in the multimeter and the digital logical experiment box .

该电路可做成 三 态 逻辑笔或装置在万用表、数字逻辑实验箱中使用。

This kind of function fine tri-state logic indicating circuit is composed of 555 integrate timer logical level threshold value adjustment circuit and the logic indicating circuit .

这种功能优良的 三 态 逻辑指示电路由555IC集成定时器、逻辑电平阈值调节设定电路、逻辑指示电路构成。