3.5 Power supplies

I declare: solidlikelyshaky

1. Explain the linear regulator, calculate what it dissipates, and say when it becomes unacceptable.
2. Explain buck and boost with the drawing of inductor, switch and diode, and what the duty cycle controls.
3. Measure a buck module’s efficiency at two different loads and compare to linear.
4. Measure output ripple on the oscilloscope and say what the output capacitor and its ESR do to it.
5. Choose a supply for a project: voltage, current, isolation, noise, and what you lose by going too big.
6. Explain the low-dropout regulator (LDO), the precision voltage reference, and protect an input against reverse polarity (diode, MOSFET) and overcurrent (resettable fuse).
7. Diagnosis: a supply that restarts in a loop, overload, hiccup protection or tired input capacitor.