An astable with 555 will be almost nondependend of voltage variation because the switching thresolds are at 1/3 and 2/3 of Vcc, whatever Vcc would be. Vasile On 9/22/08, John Waters wrote: > > Hi All, I want to use a solar cell to drive a transistor based Astable Multivibrator, obviously the Vcc won't be very stable (when circuit draws current, Vcc will drop a bit, or when light intensity changes, Vcc will change as well). I want to know if the frequency of oscillation will be affected. I guess it won't since all text book mentioned that the frequency is related to the RC value but not Vcc. Am I correct? > > Thanks in advance! > > John > _________________________________________________________________ > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist