Quote:
|
Not exactly, what you are hearing are two different things. The high frequency you hear in a flash charging is the actual oscillator used in the DC-DC converter. It changes frequency because the feedback that causes oscillation is dependent on load current. As the capacitor charges the load current becomes less so the frequency rises.
|
I was under the impression that microphony referred to the effect you're describing. I guess it's sometimes called a "reverse microphonic" effect. But in any case, I know how the effect works, I just don't know what it's called. The two phenomena are essentially the same, there's a high-frequency electrical oscillation in both cases which causes the physical coils to vibrate.