Car amp?

icecoolwas · 31st January 2009, 02:47 PM

How Much RMS can be obtained from a class D amplifier with 12V @ 60A? approx

CHEERS

Saturnus · 31st January 2009, 03:17 PM

Depends on impedance and effeciency.

Maximum Power Output = voltage ^ 2 / impedance * effeciency

This gives the theoretical maximum output at 100% distortion.

To get a realistic value at roughly 1% distortion multiply that number with 0.8.

To get the RMS output double impedance.

Anthony C Smith · 31st January 2009, 03:27 PM

power (rms) = (V^2/2R)*efficiency for a sine wave since Vrms = Vpeak/root2.
regards

icecoolwas · 31st January 2009, 03:57 PM

Sorry I dont understand this..

But the Impendance is 2ohm.

Saturnus · 31st January 2009, 04:54 PM

Ok then, let's also assume that effeciency is 80% which is typical for a class D playing into 2 ohms impedance

Then ...

Watt (peak) = 12 * 12 / 2 * 0.8 * 0.8 = 46.08

and

Watt (rms) = 12 * 12 / 4 * 0.8 = 28.8

31st January 2009, 02:47 PM	#1
icecoolwas diyAudio Member Join Date: Apr 2008	Car amp? How Much RMS can be obtained from a class D amplifier with 12V @ 60A? approx CHEERS

31st January 2009, 03:27 PM	#3
Anthony C Smith diyAudio Member Join Date: Jun 2005 Location: Sunderland	power (rms) = (V^2/2R)*efficiency for a sine wave since Vrms = Vpeak/root2. regards __________________ Anthony C Smith MAES MinstSCE -I think rain is wet so who am I to Judge-

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31st January 2009, 03:17 PM	#2
Saturnus diyAudio Member Join Date: Jun 2005 Location: Copenhagen, Denmark	Depends on impedance and effeciency. Maximum Power Output = voltage ^ 2 / impedance * effeciency This gives the theoretical maximum output at 100% distortion. To get a realistic value at roughly 1% distortion multiply that number with 0.8. To get the RMS output double impedance.

31st January 2009, 03:57 PM	#4
icecoolwas diyAudio Member Join Date: Apr 2008	Sorry I dont understand this.. But the Impendance is 2ohm.

31st January 2009, 04:54 PM	#5
Saturnus diyAudio Member Join Date: Jun 2005 Location: Copenhagen, Denmark	Ok then, let's also assume that effeciency is 80% which is typical for a class D playing into 2 ohms impedance Then ... Watt (peak) = 12 * 12 / 2 * 0.8 * 0.8 = 46.08 and Watt (rms) = 12 * 12 / 4 * 0.8 = 28.8

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