# Time constant of capacitor bank

Discussion in 'General Electronics Chat' started by sp2821, Jan 28, 2014.

1. ### sp2821 Thread Starter New Member

Jan 8, 2014
17
0
Dear all,

During charging (when switch closes), do R1 and R2 have any effect on Vout's time constant?
I initially thought $\tau$=R*(C1//C2). But it looks like R1 will affect C2 and R2 will affect C1.

Similar questions for discharging,
when switch opens, do R1 affect C2 and R2 affect C1?
Or are they independent and have different time constants $\tau$1=R1C1 and $\tau$2=R2C2?

File size:
25 KB
Views:
31
2. ### MikeML AAC Fanatic!

Oct 2, 2009
5,451
1,070
It is more complicated than you think. Note that with R = R1 = R2, after the dust settles, the voltages at a, b, c are determined by the three-high voltage divider. Notice the peaking on V(c) with the time constants I chose, .

• ###### D154.jpg
File size:
183.9 KB
Views:
22
Last edited: Jan 28, 2014
3. ### alfacliff Well-Known Member

Dec 13, 2013
2,449
429
they are to equalize the charge on the caps, not really to have a specific r/c time constant. also, they discharge the caps when the power is removed. (bleeder resistor)