FIGURE 38. SOLUTION FOR UNIVERSAL TIME CONSTANT PROBLEM.

two one hundredths), then the time required to reach one RC time

constant must be equal to:

.22 RC = 100 microseconds

1 x 100 microseconds

RC =

.22

100 microseconds

RC =

.22

RC = 454.54 microseconds (rounded to

455 microseconds)

RC = 455 microseconds

Now use the following formula to find C:

R C

C = _

R

455 microseconds

C =

20,000 Ohms

C = 0.0227 microfarads

C = 0.023 microfarads

To summarize the above procedures, the problem and solution are

shown below without the stepbystep explanation.