log
Guest
Wed Jun 01, 2005 11:19 pm
For those experts in the timer ic LM555. What value of
potentiometer should I use for Ra, Rb, and C so I can
vary the frequency from 0.1 to 100Khz. What combination
did you use and why?
Anyway. This is the formula f=1/T=1.44/ [(Ra+2Rb+C]
Thanks.
log
log
Guest
Wed Jun 01, 2005 11:57 pm
Btw... in the above I was referring to Astable Operation
Mode in the Lm555. When calculating. What is the units
of resistance and capacitance For example. I have
the value
Ra=10K
Rb=54K
C=0.1 uF
Formula: f= 1.44/[(Ra+2Rb)C]
for the above values...
f= 1.44/[(10,000 ohms + 2(54,000))x 0.0000001 F]
= 1.44/[0.0118]
= 122 Hz
Right?
log
log wrote:
Quote:
For those experts in the timer ic LM555. What value of
potentiometer should I use for Ra, Rb, and C so I can
vary the frequency from 0.1 to 100Khz. What combination
did you use and why?
Anyway. This is the formula f=1/T=1.44/ [(Ra+2Rb+C]
Thanks.
log
