Hello, with my limited knowledge I'm trying to devise a way to sense the load impedance on the output of an audio amplifier without affecting the output signal.
For example, if a pair of headphones changes impedance based on frequency I want to create a servo to adjust the output accordingly.
The main problem I have right now is figuring out how to measure the impedance, maybe using some sort of current sensing or something but I wouldn't know how to go about that and not mess with the signal. Especially since current sensing methods that I see seem to rely on having dc voltage on the input. The resistor (headphones) will only have ac voltage across it.
Maybe I can measure the rms of the ac voltages and use that to determine the load impedance? The ac rms should change with changing impedance. The issue then is how do I build a servo that functions off of rms rather than direct voltage measurements.
Any ideas?
Mods edit:
Please don't do double post.
Another post, please refer to : Amplifying DC milivolts to volts.
For example, if a pair of headphones changes impedance based on frequency I want to create a servo to adjust the output accordingly.
The main problem I have right now is figuring out how to measure the impedance, maybe using some sort of current sensing or something but I wouldn't know how to go about that and not mess with the signal. Especially since current sensing methods that I see seem to rely on having dc voltage on the input. The resistor (headphones) will only have ac voltage across it.
Maybe I can measure the rms of the ac voltages and use that to determine the load impedance? The ac rms should change with changing impedance. The issue then is how do I build a servo that functions off of rms rather than direct voltage measurements.
Any ideas?
Mods edit:
Please don't do double post.
Another post, please refer to : Amplifying DC milivolts to volts.
Last edited: