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If DC in houses became popular, it seems like they'd follow the same model as RV's -- low power devices like lighting, water pump, maybe refrigerator all run o
by Johnny555 3y ago
If DC in houses became popular, it seems like they'd follow the same model as RV's -- low power devices like lighting, water pump, maybe refrigerator all run on 12VDC, high power devices like air conditioning, microwave, etc run on 120VAC (sometimes inverted from battery).
That limits the high gauge wire to the short run from battery to inverter, otherwise you'd need very expensive and heavy large gauge cable running to those high power devices.
- amelius 3y agoWhy not step up the DC voltage instead of inverting to AC?
- Johnny555 3y agoIt's harder to step DC than AC, you'd probably end up using a switching power supply, which gets you most of the way to an AC inverter.
- amelius 3y agoYes, but once you have DC your losses will be less.
- Johnny555 3y agoLess than what? If you're converting DC->AC->DC to step it up, why not just convert DC->AC next to the battery, then AC->DC or just use the AC directly like you would in a motor at the point of use?
- amelius 3y agoBecause with a large DC voltage you have less transmission losses than with a comparable AC voltage.
- amluto 3y agoI think that, if DC appliances as used in RVs became genuinely popular, they would move to reasonable voltages. 12VDC is absurd. 48VDC would be much, much better.
- friend_and_foe 3y ago12v is perfectly reasonable for lighting, fans and water pumps.
- amluto 3y ago12V is reasonable for lighting on a small scale. It’s not really fit for purpose for lighting on a house or garden scale. (It’s not even really awesome on a small scale - nice LEDs chips and board vary between 4 and 50V or so and should be driven at constant current. With a 12V supply, this requires a buck-boost converter. With a 48V supply, most bases are covered with a simpler buck converter.) And 12V in a vehicle makes little sense if the vehicle’s battery operates at 24V or 48V — it requires DC/DC conversion for no real benefit.