Comment on [discussion] DC (direct current) power network

lemming741@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

• gandalf_der_12te@lemmy.blahaj.zone ⁨3⁩ ⁨weeks⁩ ago

  do you have a source for that?

  I know about the buck/boost DC-to-DC converters, but they don’t really use AC internally.

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  • lemming741@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    Is a square wave not AC? Current is flowing in and out of an inductor 100k times a second.

    Could that 100khz square wave excite a transformer and produce usable current on the secondary? Absolutely it could, and that’s how a bigger SMPS works.

    If you’re looking for a “pure DC to pure DC” converter, that’s called a linear regulator and it’s wildly inefficient. They work by varying the conductance of a transistor but are useful for low currents. The extra voltage is converted to heat.

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    • nixcamic@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      It’s more pulsed than alternating IMO. It never goes negative, and there isn’t a consistent frequency.

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      • lemming741@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

        It depends where you measure. If you measure across the inductor, it absolutely goes negative.

        The frequency is generally fixed, the duty cycle will vary.

        A variable speed drive can be fed with DC. Is the output AC or DC? I know you need a three phase AC motor to wire up to it.

        Is audio DC? It doesn’t have a fixed frequency. Amplifiers pulse DC and then remove or ‘block’ the DC offset so speakers see AC.

        It seems like people in this thread have a very strict definition of AC being a 60Hz sine wave, and everything else must be DC.

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