Measuring amplifier power via clamping

This video demonstrates the inaccuracies that can be encountered when trying to measure amplifier power into a speaker load via the "clamping" method.

• Category

  Science & Technology

[Amber00Dak]

you sir are awesome. in all the years ive been into car audio i have NEVER seen so many extremely useful products being introduced at one time. hats off to you, steve and all the other guys that are thinking up these devices and making them possible.

[DAmoreEngineering]

Thanks man

[omfgg3tlost]

when will the im sg be out? i want to start a new build in a few months and want to use it for the build. sould i wait? and est. price even a broad price range

[DAmoreEngineering]

IM-SG will be shipping early October 2012. In full production right now

[bigdwiz]

Awesome! My method with using the DD-1, true RMS meter/o'scope and wirewound resistors should give a similar result to the Amp Dyno, correct?

BigDWiz - OldSchoolStereo-com

[Scarface ITA]

Great video, thank you!

However, is there any way to know the power factor without having to measure it with an oscilloscope or a multimeter featuring the cos(phi) function?

I only have a normal multimeter, which can measure voltage and current both in AC and DC and of course it can measure the resistance, thus the impedance module at a given frequency. Is there any way to calculate phi, maybe by using the relations between Re and Z of the impedance triangle? Thank you very much for answering ;)

[armandoes]

I have a question: Why does the voltage keep rising when clipping?, doesn't that mean that the amp isnt't able to output more power, hence not rising the voltage?. I cant picture how can we get more power when its dirty. I can only think of a signal getting "dirtier", but not higher + dirtier.

Sorry it this is some rather stupid question, I´m not an engineer. Also excuse my english. Regards

[DaWhiteNoise1]

This is great, Thanks

[Javier Duque]

haha i love this guy, great vid!!!

[43havoczone]

I would love it if you could test out some old school amps

[CarAudioAdvice]

Goodstuff!

[bigblackbronco1979]

Tony, I've learned more from watching your videos and reading your posts on FB/SMD boards than I could have ever hoped to have learned any other way. Thanks for breaking it all down and keeping it simple. Thanks for the innovative new products like the DD-1, the T15k, and the amp Dyno.

The car stereo game is in your hands.

[splaudio1]

i need to do some heavy reading then i shall too understand this subject more, it apears that once i finally took time to properly learn how to clamp , it was not even correct , i know i will def be adding the amp dyno to my test bench

[soundforceaudio]

Well Tony is right all the way , some people are confusing the Apparent power (VA) with Real power (W) but in the case that you have a reactive load , in this case inductive , then you have a lagging power factor to deal with , because you have an amount of Reactive power (VAR). P=V.I only for purely resistive loads when the cos(f) = 1

[DAmoreEngineering]

1/35 =  1 second / 35 cycles = .02857 seconds per cycle = 28.57milliseconds per cycle.