TI App note Pdmax Equation

[MikeWhy]

TI AN-1192 gives Equation 1
Pdmax = VCCtot^2/2π^2RL

What's this pi squared stuff? Root 2 I would understand. But why pi squared?

Thanks.
Mike.

 

[rayma]

You asked for it.
http://www.seas.upenn.edu/~ese319/Lecture_Notes/Lec_21_Class_B_Amplifier_08.pdf

 

[MikeWhy]

On the contrary. Many thanks. Slides 10 and 11.

 

[rayma]

Short answer: calculus has a habit of making Pi appear where you'd least expect it.

 

[MikeWhy]

What else do you have? The syllabus for that course looked pretty interesting.

 

[rayma]

That's all from them, but try MIT free courses.
Find Courses by Topic | MIT OpenCourseWare | Free Online Course Materials

 

[jazbo8]

Guys - please stop quoting the post directly above yours when replying!
See diyAudio Rules

 

[PRR]

pi because we "assume" Sine wave. SIN and pi go together.

 

[wg_ski]

Average current is 2/pi times the peak current for a half-sine waveform. (More correctly, peak current is pi/2 times the average but whose counting). Average D.C. Power draw from a constant voltage is the D.C. Voltage times average (not rms) current. That's where the pi comes from.

2/pi is close to root 2 over 2, but not exactly. Some would call it close enough.