[R-390] 6080 in place of 6802 - RMS ???

[Barry L. Ornitz]

Rodney,

You need to go back and understand the true meaning of RMS 
- root mean square.  You have to square the waveform before 
the averaging, then take the square root of the result.  
Adding the diode in series gives half the power, but you 
have to take the square root to get the equivalent 
voltage.  Thus the figure 0.707 or the square root of one 
half.

> Rule of thumb is, if you apply the voltage for half the 
> cycle, then you get half the current over a full cycle 
> (AVERAGE). 

This is correct.  You get half the power.  But remember 
that RMS is the voltage that produces the same power as if 
it were DC.  But power is V*V/R.  Note the squaring.

Half-wave rectified 26.5 volts AC produces the same 
filament temperature as 18.74 volts DC or 18.74 volts RMS.

Feel free to look this up in any electrical engineering 
text.

        Dr. Barry L. Ornitz     WA4VZQ          ornitz@tricon.net