how to get an average voltage from 2 sources?

[Qwerty]

I have an application where I have 2 supply sources vary in range of 300mV-800mV.

I need a circuit that can take these 2 signals and output the average voltage of both. Can it be done fairly simply?

thanks
Tim

 

[Mark Little]

I think you need explain what you want in more detail.

What exactly do you mean by "the average voltage"? Are you wanting to add
the two voltages up and divide by 2? - that will give you the instantaneous
average voltage. Are you wanting the average over a time time period, say, 1
second, 1 hour, 1 day?

In the first instance, all you need is a summing op-amp circuit with the
gain set at 0.5. Any decent book on op-amps will show you how to do that. If
you want to time average, it will be a bit more complicated as it depends on
how long you want to average over. If it is a relatively short period of
time, you can use an integrator to get the average, but it is it a long
period of time, it may be easier to digitise the result and use a PC get the
get the average.

regards,
Mark

I have an application where I have 2 supply sources vary in range of 300mV-800mV.

I need a circuit that can take these 2 signals and output the average

voltage of both. Can it be done fairly simply?

 

[Phil Allison]

"Qwerty"

I have an application where I have 2 supply sources vary in range of 300mV-800mV.

I need a circuit that can take these 2 signals and output the average voltage of both.
Can it be done fairly simply?

** Yep - with just two ( say 10 kohm) resistors, one end of each
connected to the voltage sources and the other ends joined. The voltage at
the join will be the ( instantaneous) average value as read on a DVM.





............ Phil