Power Amplifier Voltage & Current Level

[Lory]

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

I build a function generator using the IC XR2206. It's
current is so low I can't even drive a bulb of light
with it. So I plan to boost the voltage and current
by plugging it to a power amplifier. I need a voltage
10V or above. I wonder what is the average voltage
rating of a power amplifier. Is it dependent on the
wattage or power rating? How do I know its respective
voltage and current?

Thanks.

Lory

 

[Ken Taylor]

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

I build a function generator using the IC XR2206. It's
current is so low I can't even drive a bulb of light
with it. So I plan to boost the voltage and current
by plugging it to a power amplifier. I need a voltage
10V or above. I wonder what is the average voltage
rating of a power amplifier. Is it dependent on the
wattage or power rating? How do I know its respective
voltage and current?

Thanks.

Lory

Do you actually want to vary a light bulb's intensity or are you using that
as an example? Since you built the generator you may like to look up some of
the amplifier IC's that are available, such as the LM386.

Ken

 

[Tomi Holger Engdahl]

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

The power to a load can be calculated with voltage
and resitance values with equation

power = (U * U) / R

Where U is the voltage and R is the resistance

This becomes U = sqrt( power * R)
In this case the voltage with 750W @ 4 ohm load would
be around 54.8 V. That's the RMS voltage.
The peaks go to around +-77V.

I build a function generator using the IC XR2206. It's
current is so low I can't even drive a bulb of light
with it. So I plan to boost the voltage and current
by plugging it to a power amplifier.

That's a good idea. A normal audio amplifier works well
with function generator as long as you work within the
frequency response of the amplifier.

I need a voltage 10V or above.

The amplifier you have can definately give that.

I wonder what is the average voltage
rating of a power amplifier. Is it dependent on the
wattage or power rating? How do I know its respective
voltage and current?

I answered those in the example above.

 

[Boris Mohar]

Since Urope started using it. Pretty soon all electrical products shipped to
Urope will have to Uoltage ratings specified.

 

[Ken Taylor]

Since Urope started using it. Pretty soon all electrical products shipped
to
Urope will have to Uoltage ratings specified.

V haue to be kidding!

Ken

 

[Tomi Holger Engdahl]

Dependign on what books or other references you read you can
see letters U, E and V used to mark voltage on the equations.