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Hi guys and girls....
Just wondering if you can help me with some basic maths.
I have programmed a chip for some simple phase control however I need to workout the average power given the firing angle.
searching the internet I found the equation:
average power = Vpk/4*pi*R [pi - angle+1/2*sin(2*angle)]
I HAVE NO IDEA HOW TO TYPE THIS INTO A CALCULATOR!
The angle 1/2 bit does my head in. Can somebody please translate this equation to a simpleton and do it as simple as possible.
cheers..
Hi, That's not too difficult ... to use it with PBP
1) Pi (3.141592654 ...)
replace it by integer fraction like 22/7 or 355/113
2) here, angles are expressed in radians ... just change to BINARY radians PBP can deal with
2*pi rads = 360° = 255 binary radians ...
and keep a sharp eye on overflows ( depending on the processor used : 16F - 16 Bits unsigned, 18F with longs - 31 signed bits )
That's all !!!
looks it applies to a resistive load ( lamp, heather ...) but not to inductive loads ... like motors.
Alain
Thanks for your reply Alain but before I can try to implement the equation into the programme I need to know how to calculate it with a calculator.Quote:
Originally Posted by Acetronics
Attachment 6221
The answer is meant to be 480W but I don't get close to it. The bit in brackets comes out with a negative number??
Should have stayed at school I guess..
The angle needs to be in radians. If you multiply the angle in degrees by Pi/180 you will get the angle in radians.
When you do so, it comes out to 480. (http://www.wolframalpha.com/input/?i...5*(Pi%2F180))))