You're right. Don't need MathCAD to see it; square root of half is
..707. Half as many pulses deliver half as much power.

I think DC motors respond to average voltage rather than RMS voltage
to determine their no-load speed,

On Mon, 29 Nov 2004 20:56:04 GMT, Ted Edwards
wrote:


Peak is still 34V but rms is 17V not 12V. Feed it to MathCAD and you'll
see:
Sqrt((1/2pi)Integral{(Sin t)^2}[0,2pi] ) = 0.707
repeat multiplying the integrand by Sin(t)0 for half wave and you'll
get
0.5 not 0.35. Not surprising since peakier waves have a higher rms/avg
value. The _average_ voltage of half wave is half the average value of
full wave but that doesn't work for RMS.

Ted