555定时器阈值电压自浮动的探讨

Self Floats Study for Threshold Voltage of 555 Timer

阈值电压决定555IC定时器输出电压的翻转时刻。把555IC输出端或辅助输出端的电压反馈到电压控制输入端,形成输出的数字信号反馈,使内部2个比较器的阈值电压随之浮动。利用反馈使阈值电压自浮动的原理,可在不改变外部时间常数的情况下,把555IC的定时时间延长3倍左右,使定时电路得以简化,降低制作成本,是555IC延长定时时间的一个新思路。

Threshold voltage decides the output voltage turning time of 555 timer.Voltage of 555IC fanout or assistant fanout feeding back to input for voltage apron string,forms deferent DS feedback,and holds threshold voltage inside two comparators to float along with.Using theory of feedback and threshold voltage self float,can,without the alteration of exterior time invariable circs,prolong timed time of 555IC by threefold and reduce cost.