Brief background, I studied physics in college and am learning EE on-the-job through Art of Electronics and this wonderful website.
So this is a follow up to a previous question I submitted here yesterday. I was trying to see what could have gone wrong when I wired a bunch of devices in parallel and then ran them under-voltage. In the comments, I was informed that I should pay attention to P = IV in that the devices I'm using will try to maintain a fixed power rather than respond according to V = IZ.
I'm not entirely clear on this so I was hoping someone could enlighten me as to what kind of circuit could be drawing more current in response to less voltage. I always understood current and voltage to be proportional on a fundamental level, regardless of the load, since the voltage is the energy source. But, if we take the fluid flow analogy, perhaps there's some sort of "thinning of pipes" when a lower voltage is applied.
How does a circuit pull more current when it doesn't get the voltage it wants with respect to a constant minimum power?
What kind of circuit keeps a constant power?