NE555N/NE555D
comparator output on the trigger terminal becomes high and the timer output becomes high
again. The discharging Tr. turns off and the VC1 rises again.
In the above process, the section where the timer output is high is the time it takes for
the VC1 to rise from Vcc/3 to 2Vcc/3, and the section where the timer output is low is the
time it takes for the VC1 to drop from2Vcc/3 to Vcc/3. When timer output is high, the
equivalent circuit for charging capacitor C1 is as follows:
Since the duration of the timer output high state(tH) is the amount of time it takes for the
V
C1(t) to reach 2Vcc/3,
The equivalent circuit for discharging capacitor C1,when timer output is low is ,as
follows:
Since the duration of the timer output low state(tL) is the amount of time it takes for
the VC1(t) to reach Vcc/3,
7/11
TGS [ Tiger Electronic Co.,Ltd ]
