Voltage and Current Peak Detector

[gdan]

This is a simple portable device that can help answer the question about peak voltage and peak current requirements and whether or not your power amplifier is capable of driving your loudspeaker without clipping.

This device was descried in an article originally published in AudioXpress March 2015.

Joao Martins, Editor-in-chief of Audioxpress magazine was very kind to post the article on line. You can find it here:
You Can DIY! Build a Voltage and Current Peak Detector | audioXpress

If you are interesting in building this device, you can find usefull information here:
http://www.diyaudio.com/forums/swap-meet/276985-pcb-peak-voltage-current-detector.html

 

[31697B]

Are there any completed/build units for sale?


-RNM

 

[gdan]

Yes, this could be arranged.

I will send you a private message with the details.

regards
George

 

[Kiriakos]

I can not feel the magic regarding usability.
One good modern Oscilloscope this is tremendously faster to detect peak volts.
And also a modern multimeter that is capable for VFD/ Low pass filter, this can measure peak ampere (60Hz ~ 2KHz) .
And such two equipment by working and displaying simultaneously they do deliver the all picture (real time).

 

[gdan]

For those that have built the Peak detector, I suggested a modification to the original article here:
You Can DIY! Build a Voltage and Current Peak Detector | audioXpress

 

[tauro0221]

Hi,
I do not know but this can be easily done using a micro. Just read the voltage and current and then print/display it in a graphic form. That it is my suggestion ..

 

[arnyk]

Hi,
I do not know but this can be easily done using a micro. Just read the voltage and current and then print/display it in a graphic form. That it is my suggestion ..

Agreed.

The fundamental problem with this approach is that it does not detect actual clipping, but rather relies on abstract information about the amp's current and voltage capabilities.

Amp capabilities are usually dependent on a number of variables including speaker impedance and the frequencies being amplified. There isn't just one number for max voltage and current output, but more complex functions of frequncies and other variables.

It is simple enough to hook up a 'scope or comparable device in such a way that amp clipping and more subtle distortions show up as curvatures in the amp's transfer characteristic when they actually happen.

In modern times this can be done with an audio interface and recorded and analyzed when convenient.

 

[gdan]

As I said in post #1, this is a simple device that can measure the peak voltage and the peak current. It cannot replace a oscilloscope or a sophisticated system based on micros and A/D converters. Yet it is accurate, its cost is very low compared with the above systems and very easy to use.