Convert Power to a Peak Voltage, when to multiply by sqrt(2)

In summary, the average power over time for a signal is just that- average. The power can be calculated for a particular signal based on the details of the system in question.
  • #1
Natalie Johnson
40
0
I have a dBW value and dBW I understand to normally be given as representing a RMS Power (however this is not specificically ever stated and I am told its just assumed?)

from dBW to Watts = 10^(dBW/10)
This then gives RMS power in Watts

At what point do I convert this from a RMS to a peak value:

1. Multiply RMS Power in Watts by sqrt(2) before using Voltage = sqrt(Power*50)
2. Or multiply the result from Voltage = sqrt(Power*50) by sqrt(2)

because they give two different values...
 
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  • #2
There is really no such thing as RMS power. No matter what audio power amplifier salespeople tell you, power is always average, or if so spec'd, peak. Do not multiply power by 1.414. To convert the power of a sine wave from average to peak, you need to compute the voltage, multiply that by 1.414, then convert back to power. You will find that with a sine wave, peak power is double average power.
 
  • #3
Natalie Johnson said:
from dBW to Watts = 10^(dBW/10)
This then gives RMS power in Watts
etc.
This may sound a bit lame but what is the context of your question? It seems to me that you may be talking about an RF signal which is varying in level (Amplitude Modulation?). The 50 figure suggests a 50Ω RF system. The arm-wavey use of the term "RMS Power" has different meanings and differently fuzzy use in RF and Audio.
Natalie Johnson said:
and I am told its just assumed?
That proves my point! If it really means something then they would come clean and define it properly.
Power is Power. The Average power over time for a signal is just that. How that can be calculated must depend on the details of the system in question.
1. and 2. are confusing me a bit.
Try explaining the context of all this. It should become clear.
 

1. What is the relationship between power and peak voltage?

The relationship between power and peak voltage is that as power increases, peak voltage also increases. This is because power and peak voltage are directly proportional to each other.

2. How do you convert power to peak voltage?

To convert power to peak voltage, you can use the formula Vp = √(2P/R), where Vp is peak voltage, P is power, and R is the resistance in the circuit. This formula is derived from the equation P = (Vp^2)/R, where P is power, Vp is peak voltage, and R is resistance.

3. When should you multiply by sqrt(2) when converting power to peak voltage?

You should multiply by sqrt(2) when converting power to peak voltage if the power value given is the average power. This is because peak voltage is equal to the square root of two times the average power divided by the resistance in the circuit.

4. Can you convert peak power to peak voltage using the same formula?

No, you cannot convert peak power to peak voltage using the same formula. The formula for converting peak power to peak voltage is Vp = √(2PR), where Vp is peak voltage, P is peak power, and R is the resistance in the circuit.

5. Why is it important to convert power to peak voltage?

It is important to convert power to peak voltage because it allows us to understand and analyze the behavior of electrical circuits. Peak voltage is the maximum voltage in a circuit and plays a crucial role in determining the performance and efficiency of electronic devices.

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