I’m planning to add a momentary switch to a single loop DC circuit. Will this cause any amount of resistance in the circuit? I’m a complete noobie when it comes to electronics, any resource links or clarification is appreciated. I know the type of material/width of wire and a pot will cause resistance but will any component put in line with the circuit cause resistance, and if so how do I go about measuring the resistance for each component within the circuit?

  • Enclose0314
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    2 years ago

    Unless you’ve managed to get a switch made out of superconducting material and you’re working inside a liquid helium bath, everything has resistance :)

    You’ll have a bad time trying to measure such low resistances, so usually you can look at the datasheet for the switch you’re using or for a similar switch if you need a ballpark number. You’ll see an on-resistance, and a max current (since there will be arcing when you open the switch).

    If you do want to measure the low resistance, you’ll need dedicated meter with a kelvin connection.

    • cmnybo
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      2 years ago

      If you do want to measure the low resistance, you’ll need dedicated meter with a kelvin connection.

      You can pass a known current through the switch, measure the voltage drop with a multimeter and use ohms law to calculate the resistance.

    • shoeforthepotOP
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      2 years ago

      Thanks for the feedback and info, I’ll know what to look for next time. Unfortunately, I purchased a tattoo pedal as the momentary switch, thinking it would be easier to operate. link Btw. thanks for clarifying everything has resistance, that concept confused me more than I thought it would.

      • Enclose0314
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        2 years ago

        Open it up!

        They put a regular old switch inside a fancy box, but you’ll be able to read the part number once you see the actual switch.