Recent content by Wayne

Opps slight miss calculation tc=2.88ms? "-in" means natural logarithm

Ok has the penny just dropped? if formula i = I (1-e (-i/I)) Is transposed to if tc = t / ( -in ((1- (i/I))) i= 0.75 & I =1 Then tc = t / (-in ((1- (0.75/1))) tc= 1.68 ms

Sorry I totally not getting this been looking at this for a week before I decided to put it on here. I understand i is 75% of I and took 4 ms, and guessing I have to us e as the curve is expo-dental 1 tc=63.5% & 5 tc is 100%

Sorry you lost me! I don't know i as not given and can't calculate I as don't know r to calculate I=v/r

i = I (1-e (-t/tc)) i =instantaneous current I final current I=v/r

Hi all, I need your help with a Time constant question? I am studying for an exam via distance learning and don't feel they have covered this question, question taken from past paper. 2. A coil of inductance 2 H and unknown resistance is connected to a D.C. supply of 100 volts. After 4 ms the...