• deranger@sh.itjust.works
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    2 days ago

    Just learn the math, it’s quite easy. IIRC you just add the reciprocals of the resistors then take the reciprocal of the answer.

    1/Req = 1/R1 + 1/R2 + 1/R3 ….

    • Denvil@lemmy.ml
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      1 day ago

      Note that if it’s a series circuit you simply add resistance.

      I’m just an electrician though, we don’t actually use the math or the theoretical stuff terribly often

    • Lemminary@lemmy.world
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      2 days ago

      Ohh, I remember this from uni physics class. I guess I just don’t know how to apply it in any practical sense though. Lol Thanks for reminding me!

      • ggtdbz@lemmy.dbzer0.com
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        1 day ago

        The standard resistor values are a bit weird at first but when you’re in the zone and you start getting used to what they usually are you start becoming relatively decent at making an educated guess for what the values should be. The actual IRL values are predictably defined and you start remembering the possible options over time.

        Someone’s probably made a program that can do it for you though. My own shitty circuits are all built from standard example circuits so I haven’t had to think about this stuff often. Or like I’ll mix and match them illogically in a pinch (on the breadboard) and figure it out later (I don’t build the final circuit lol). Or of course, the venerable using-a-potentiometer-exactly-where-you-shouldn’t technique, which is one of the pillars of modern engineering.

        • Lemminary@lemmy.world
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          1 day ago

          you start becoming relatively decent at making an educated guess

          Oh, this reminds me of a guy who could guess hexadecimal colors by eye after doing it for a while, and also another guy who could guess some concentrations in a test tube without using the spectrometer. Kinda wild but it makes sense.