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This is something that always caught my imagination: using DC for the last mile. I don't understand electricity well, but it seems that electronic components r
by hrjet 12y ago
This is something that always caught my imagination: using DC for the last mile.
I don't understand electricity well, but it seems that electronic components require regulated DC, and producing that requires an AC somewhere in the transforming circuit. Is that correct?
- dreamcompiler 12y agoIn a sense, you're right. Although it's perhaps not the style of AC you were thinking of. Inside every DC-DC conversion circuit there's one or more energy storage elements charging and discharging repeatedly. This internal waveform is AC. It's not sinewave AC, but it's technically alternating current.
- m4x 12y agoNo, you can generate 'regulated' DC from another DC source (see for example buck converters or more generally any DC-DC converter). Regulated really just means clean DC which stays at the same voltage and doesn't contain a lot of noise. Not all devices require a regulated supply. A drill, torch or heater will happily run on a noisy supply. Your iPhone will not.
- deleted 12y ago[deleted]
- hrjet 12y agoYou are right. I remember more details now. The problem occurs when you want to make regulated DC from a lower voltage DC supply. Step-down is easy. For example, my battery is 12V, but my laptop needs 19V. AFAIK, you can't get regulated 19V supply from the 12v battery without a transformer (or maybe something equivalent).
- dreamcompiler 12y agoStep-up is easy too. That's what boost converters (http://en.wikipedia.org/wiki/Boost_converter http://en.wikipedia.org/wiki/Boost_converter) are for. Most single-cell LED flashlights contain tiny boost converters to increase the 1.5v coming from the battery to above the drop voltage of the LED.