Re: RMS Voltage
Hay, it was ok as far as you went but there is a lot more... RMS is a useful number and is calculated as you said, or by multiplying peak voltage by 0.707 and that is useful because electrical loads which convert electrical energy to heat, such as incandescent light bulbs, or heating devices, produce the same amount of heat from the 460 volts rms in your example as they would produce if 460volts DC were applied! But loads which work magneticaly react differently, they respond to the true arithmetic average of the voltage, that is calculated using the formula peak voltage times 0.636. many things electrical including motors, analog (De'Arsnoval) meters, and of course electromagnets, work magneticaly and the magnetic field strength follows the average value, not peak or RMS. Also note we are both using a "SINE WAVE" as our example, any other waveshape uses different constants to calculate RMS or Average! Oh yeah, a capacitor will charge up to peak after a couple of alternations if the voltage doesn't change in polarity. And LED light brightness follows Peak voltage and if powered by AC or Pulsating DC our human eyes remember the brightest part of the glow even if they are flickering, at any rate above 40 flashes per second. That is called "Persistance of Vision."
Last edited by Engineering Manager; 09-26-2008 at 08:29 AM.
Reason: spelling and grammar corrections