2. tech-talk
  3. 130312-26

RMS Power?

I often see power specifications like "100W RMS".  There is no such thing as RMS power.  Of course, you can calculate RMS value from any curve, including power curve, but it won't represent anything.  "Real" power representing heat dissipated in resistive load is "Average Power"   Pavg=Vrms*Irms.   In case of sinewaves Pavg=0.707Vpeak * 0.707Ipeak = 0.5Ppeak,  or Ppeak = 2Pavg. 

Term "RMS Power" or "watts RMS" is a mistake, very common in audio.
128x128kijanki
kijanki's avatar
kijanki OP
3,575 posts
 

Output impedance term can be complex. Perhaps we should rate it in ohms RMS for clarity? :)



williewonka
1,826 posts
 
@kijanki -

Wliliewonka - It is "watt" and not "Watt" (units start with small letter - but I’m sure you don’t care). You can go back to sleep now.

Peace - I really have no quarrel with you.

Might I suggest that since you have so eloquently demonstrated the incorrect use of the term - that you try contacting at least one of the offending manufacturers and ask them why they still elect to use this invalid term.

"We" might all agree that it is incorrect. But it does no good to preach to the choir.

Perhaps some feedback from the industry could shed some light as to why they continue this practice?

Without it, the reasoning behind it's continued use is just conjecture.

Regards... 
kijanki's avatar
kijanki OP
3,575 posts
 
Williwonka, Peace!  I'm sorry for the tone of my comments toward you.  
Changing industry might not be possible, but we can start with our forum.
williewonka
1,826 posts
 
@kijanki - all is OK! - I sort of asked for it :-)
asvjerry's avatar
asvjerry
609 posts
 
When it comes to watts, there never seems to be enough to satisfy some, regardless of how it's measured.
Ultimately, if you can't stay in the same space with it, it ought to be enough.  Unless you're hooked on the smell of things starting to fry.  Then I'd suggest you might need a therapist instead of more wattage.

Just teasing,  but MHO...;)
More to discover