Author Topic: Power Amp Input Offset Voltage  (Read 563 times)

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Offline Bronco Leonard

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Power Amp Input Offset Voltage
« on: December 24, 2016, 07:02:35 am »
I'm building an ultrasonic varmint stay-away using a sine wave generator feeding a mid-sized, mid-quality auto power amp.  My question is this:  I've tried two different sig gen circuits and both make a nice sine wave, but they both have a DC offset of several volts.  Will this bother the power amp, or would any reasonable amp have a dc filter built into it's input circuitry?

If I have to block the dc myself, would a simple RC filter set to 500 hz do the job?

Edit:  I forgot to mention that I am using an old XR-2206 for signal generation.  Does it have a built-in way to control the output offset voltage? 
« Last Edit: December 24, 2016, 08:07:17 am by Bronco Leonard »
 

Offline danadak

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Re: Power Amp Input Offset Voltage
« Reply #1 on: December 24, 2016, 10:59:09 am »
You have to check the specs of the Amp to see if its DC coupled.
Most are not, but check.

You can DC offset a signal, here is one method using 2 R's, and attached a calculator
to determine their values. Notde the zip file has other stuff in it as well for other prob-
lems.

https://www.dropbox.com/s/k1yn4m7heaixvmg/ADinput%20negative%20inputs.zip?dl=0


Regards, Dana.
Love Cypress PSOC, ATTiny, Bit Slice, OpAmps, Oscilloscopes, and Analog Gurus like Pease, Miller, Widlar, Dobkin, obsessed with being an engineer
 


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