time ~ cosine :-(

Thread Starter

onlyvinod56

Joined Oct 14, 2008
362
hi every one....
iam from electrical background. I am designing power factor measurement circuit using 89c51. I want to convert the time gap between two consecutive pulses into degrees (angle = 100pi*time). then i have to get the cosine of that angle. my problem is, i didn't find any technique to get cosine of that angle. please help me.
thanQ.
 

Papabravo

Joined Feb 24, 2006
12,301
Depending on the number of entries in the table and the available memory you may have to interpolate. I did not say that a polynomial approximation was the only way, but it is a common way, as is table lookup.
 

davebee

Joined Oct 22, 2008
539
Somebody invented routines called cordic algorithms that I've heard some calculators use to generate trigonometric functions, but I couldn't explain them.
 
Top