Hi all
I am trying to get my head around this formula. It is to calculate the values of the resistors and capacitors needed to set a specific frequency of a wein bridge oscillator.
the formula is f = 1/2PiRC
Well it seems simple enough and with a bit of study I found one area I was screwing up was using the correct format for the values IE;
68K = 68000ohms 0.1uf = 100nF
Now the thing is I can do the sum but I am still not getting the answer I expect. The circuit has had its frequency adjusted to 30Hz from the original and the guy has calculated the values as;
R = 53.1K C= 0.1uF (100nF)
The sum is done as follows there may be an error due my calculator lacking the 'to the minus 9' option which I believe adds 9 zero's to the end of the 100nF so it looks like the 100*10,000,000,000 in the sum below.
1/(2*3.141592654)*(53,100)*(100*10,000,000,000) =
8,451,127,477,076,154.380388999 which is no where near 30Hz
So I am not doubting the guys got it right. Mainly because I know I am a total thick *********** when it comes to this sort of thing. So what am I doing wrong. Keep it simple because I really am thicker than thicky McThicky a very thick person.
regards
Fenris
I am trying to get my head around this formula. It is to calculate the values of the resistors and capacitors needed to set a specific frequency of a wein bridge oscillator.
the formula is f = 1/2PiRC
Well it seems simple enough and with a bit of study I found one area I was screwing up was using the correct format for the values IE;
68K = 68000ohms 0.1uf = 100nF
Now the thing is I can do the sum but I am still not getting the answer I expect. The circuit has had its frequency adjusted to 30Hz from the original and the guy has calculated the values as;
R = 53.1K C= 0.1uF (100nF)
The sum is done as follows there may be an error due my calculator lacking the 'to the minus 9' option which I believe adds 9 zero's to the end of the 100nF so it looks like the 100*10,000,000,000 in the sum below.
1/(2*3.141592654)*(53,100)*(100*10,000,000,000) =
8,451,127,477,076,154.380388999 which is no where near 30Hz
So I am not doubting the guys got it right. Mainly because I know I am a total thick *********** when it comes to this sort of thing. So what am I doing wrong. Keep it simple because I really am thicker than thicky McThicky a very thick person.
regards
Fenris
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