• brucethemoose@lemmy.world
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    1 day ago

    Shoudn’t it be 25%?

    Current is not controlled here, resistance (aka the soldering iron) and voltage are.

    Power = Voltage ^ 2 / Resistance. Double the voltage, that quadruples the power. So you only want to plug in 25% of the time to get the equivalent power of 120V.

    But it might not melt at double power? Maybe the extra heat helps, I can’t find a resistance/temperature curve for a soldering iron…

    Source: EE dropout.

        • ch00f@lemmy.world
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          21 hours ago

          In my defense, I’ve been helping a friend with an EVSE install where the load (electric vehicle) is smart. In that context, it’s just voltage X current capacity of the line = power. The rest of the story is true as far as I know.

    • uneatable@lemmy.world
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      20 hours ago

      Ok. I was acountless on lemmy for a long time, your comment made me finally register. Thanks!

      So, yeah, with double the voltage you get 4x the power. But you you put 4 times the power at 50% of the time, you get only 2x the power. And the other half of the time, you get 0 power. On the average you get the same power output.

      • ch00f@lemmy.world
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        20 hours ago

        You double counted there.

        You said 4x power 50% of the time and then said “the other half of the time.”

        So you’re calculating 50% of 50% which is 25% duty cycle.