6.7 Converters

I declare: solidlikelyshaky

1. Size a DC-DC converter for a project (48 V → 12 V, 12 V → 5 V): current, efficiency, heating, noise.
2. Measure a converter’s efficiency at three loads and find where it’s poor.
3. Explain 12 V → 120 V inverters, modified sine and pure sine, and what each does to a motor or a charger.
4. Size the wires and fuses of a small 12 or 48 V system on the DC side, and explain why DC is harder to break.
5. Measure a converter’s heating under continuous load and decide on the heatsink or ventilation.
6. Explain galvanic isolation (transformer, optocoupler) in a charger and why the tool’s ground isn’t the mains’.
7. Diagnosis: a converter that whistles and heats under a load well below its rating, thin wires at the input, low input voltage or dead input capacitor.