I'm working on my own subtle reinterpretation of an audio clipper circuit and I'd like to add metering which indicates the amount of clipping, expressed in dB.
Although the clipper circuit so far is passive, I can easily handle buffering signals, as well as rectifying and smoothing to read averages if that's helpful, so assume for the sake of argument that the inputs to the metering circuit I'd like to build are already buffered from the original source, being fed from op amp outputs.
Signals might be as high as 20VAC p-p, although 7V p-p seems more likely.
I know there are bar graph ICs that make displaying voltages in logarithmic divisions easy, but what I want to display is the ratio between two signals in dB. So 10V in, 5V out is a 2:1 ratio, and 2V in, 1V out is also a 2:1 ratio. I would want both of those signal pairs to result in the same visual bar graph display (-6dB.)
Is there a reasonably simple analog circuit that produces an output related to the ratio between two input voltages? If not, I know l can do it with a microcontroller with a few ADC inputs, and it might make sense to do that anyway, because then it's trivial to add extra features like resetable peak indicators, etc. Still, I'm curious how feasible an analog solution would be.
Any thoughts? Is this ratio display circuit a well known quantity? I did some searching and came up empty, but maybe l was just using the wrong search terms (sometimes knowing what you're searching for is the hard part!)
Although the clipper circuit so far is passive, I can easily handle buffering signals, as well as rectifying and smoothing to read averages if that's helpful, so assume for the sake of argument that the inputs to the metering circuit I'd like to build are already buffered from the original source, being fed from op amp outputs.
Signals might be as high as 20VAC p-p, although 7V p-p seems more likely.
I know there are bar graph ICs that make displaying voltages in logarithmic divisions easy, but what I want to display is the ratio between two signals in dB. So 10V in, 5V out is a 2:1 ratio, and 2V in, 1V out is also a 2:1 ratio. I would want both of those signal pairs to result in the same visual bar graph display (-6dB.)
Is there a reasonably simple analog circuit that produces an output related to the ratio between two input voltages? If not, I know l can do it with a microcontroller with a few ADC inputs, and it might make sense to do that anyway, because then it's trivial to add extra features like resetable peak indicators, etc. Still, I'm curious how feasible an analog solution would be.
Any thoughts? Is this ratio display circuit a well known quantity? I did some searching and came up empty, but maybe l was just using the wrong search terms (sometimes knowing what you're searching for is the hard part!)
