What does 250 watt RMS mean?

Answer 1

250 watt RMS stands for the abbreviation of, "root means square". This sounds like an AC circuit or an audio circuit.

For instance, if you take the voltage coming out of the wall socket and it's at 117 VAC, the true RMS voltage is: 82.718 volts, RMS.

In audio systems, there's a difference between "peak power" and the so called RMS power, and in the situation where a stereo system has 150 watts peak music power, its "RMS" power is: 106.05 watts.

How do you find out what the RMS rating is? Just multiply the peak voltage, peak music power, peak watts by .707 and you'll have the RMS power. In general terms, the RMS can equate to the actual "working power" of an AC circuit, or you can refer it to the "true power" available. Watts root mean square is the effective value of alternating current electrical power compared to direct current power. In AC there is a rms or effective value of voltage and a rms or effectice value of amperage. Power is volts rms times amps rms. That is the AC watts compared to direct current power. - - - - - - - - -

There's lots of information and maths to digest.

The key point is that rms power is "true power".

rms power = "true power" or "real power"

rms power = "heating power"

rms power = "working power"

Audio signals in a piece of music vary in amplitude, in frequency, in pitch, in tone, in wave shape, etc, etc.

How do you measure the energy in such a complex signal...?

Here is a very silly analogy to help, but is not to be taken as accurate, only as a rough guide.

Strictly speaking, there is no such a term as rms power, never-the-less, it is commonly used in audio circles.

Forget the maths and science for a minute ...

Imagine hundreds of bicycles fitted with dynamos, back wheel suspended, bicycle fixed to the ground, bums in the air. The sole purpose of this exercise is for every cyclist to pedal and to produce electrical energy.

Each cyclist is asked to pedal as leisurely, as often, as intermittently, as rapidly, as variable as he wishes, in his own time.

How on earth do you measure the total combined enery being produced...?

There are perhaps 600 cyclists all doing their own thing.

If we connected all 600 dynamoes to a heating element, the resultant heat produced will be the true power generated, the "rms" energy.

There cannot be RMS power or watts RMS. Scroll down to related links and look for "Why there is no such thing as 'RMS watts' or 'watts RMS' and never has been". RMS watts is meaningless, but we use that term as "an extreme shorthand" for power in watts calculated from measuring the RMS voltage.