/diy/ - Do It Yourself

>>1712998
it can be hard to find multiple-output supplies in just the flavor you like because the quantities aren't there and the output ratios and currents are dependent on the magnetics. if recycling old PC equipment isn't acceptable, I'd get the 12V and derive the 5V from it with a thicc buck converter

>>1713085
now there's a cute way to get kids into power electronics
>not using a primary winding of an old alarm clock's power transformer as a 200mH inductor
>I don't have junk, what do?

my "Saleae" logic analyzer knockoff failed to save me a couple of hours this evening. because I didn't use it. I thought I was being so clever and forward thinking, setting up that USART for even parity and promptly forgetting I did. Pic related

>>1705678
>maximum voltage
there isn't really one. inductors deal in current
>a way
not really. you might be able to make some stupid estimates of power dissipation for the series LC and its parts over frequency and judge whether it's reasonable for the package

Okay I know this is a retarded question but I don't know jack about electronics so bear with me.
After reading about Ohm's law I was left with the impression that the voltage is always equal to the resistance times the current. However, I own several phone chargers; one is rated at 5V/1.5A, another is rated at 5V/2.1A and and another is rated at 5V/1A. I can use the same USB cable to connect each charger to my phone. Since the voltage and resistance of the cable remain constant, how can the amperage change? Do smartphones have some built-in dynamic resistor that can adjust the resistance to match the rating of the charger?? If that's the case, does it have a technical name I can look up to find out how it works