Please help.
I have made a circuit with a 15micro farad capacitor and 100K ohm resistor in order to see how long it would take to charge the capacitor.
Mathmatically using:
VCap = V max (1-e –t/cr) it should read e to the power -t/cr, but can't superscript.
1 time constant is 1.5 seconds and so 5 is 5X1.5 = 7.5 seconds.
However, in one of Paul Lewis' excellent tutorial videos, he says to work out the second time contant you have e to the power of -2, and the third time constant you have e to the power -3 etc. When this method is used 5 time constants = 10.608seconds opposed to the 7.5 seconds above.
Why the difference?
I have made a circuit with a 15micro farad capacitor and 100K ohm resistor in order to see how long it would take to charge the capacitor.
Mathmatically using:
VCap = V max (1-e –t/cr) it should read e to the power -t/cr, but can't superscript.
1 time constant is 1.5 seconds and so 5 is 5X1.5 = 7.5 seconds.
However, in one of Paul Lewis' excellent tutorial videos, he says to work out the second time contant you have e to the power of -2, and the third time constant you have e to the power -3 etc. When this method is used 5 time constants = 10.608seconds opposed to the 7.5 seconds above.
Why the difference?
