I have been studying about the capacitance required for the smoothing filter of a rectified circuit and I am having difficulty understanding the following.
In a post by thingmaker3 [ 3rd post down @ http://forum.allaboutcircuits.com/showthread.php?t=12878 ] he states "Rule of thumb for calculating power supply filter capacitors: C = 0.7(I)/DE(f)". Other posts I have read also indicate similar formula.
However, I cannot figure out where the "0.7" factor in his equation comes from.
If I understand the derivation provided in the textbook I am studying on the subject, there should be no factor at all in the equation.
Can anyone help me understand the discrepancy?
Thank you in advance for your help!
In a post by thingmaker3 [ 3rd post down @ http://forum.allaboutcircuits.com/showthread.php?t=12878 ] he states "Rule of thumb for calculating power supply filter capacitors: C = 0.7(I)/DE(f)". Other posts I have read also indicate similar formula.
However, I cannot figure out where the "0.7" factor in his equation comes from.
If I understand the derivation provided in the textbook I am studying on the subject, there should be no factor at all in the equation.
Can anyone help me understand the discrepancy?
Thank you in advance for your help!