are they the words for the same thing? When we say ‘connect to ground’ does that mean the same as connect it to the negative terminal of the battery?
Or do we connect a ground pin TO the negative terminal of a battery. Such that if we have multiple devices, and we connect them to the same ground pin, all the current can sink into the negative terminal of the battery? As it should?
MAINLY IN REGARDS TO ARDUINOS.
In: 1
“Ground” is a fungible term in electronics, but it generally means one of two things:
* Earth ground- a current path of last resort for fault current. This is the third prong on an electrical outlet, and is not normally part of the flow of current in a properly functioning circuit.
* The “negative” side of a DC power supply. It can also be called “common”.
Current in a circuit needs to flow in a circle, or it doesn’t flow at all. Current technically flows from negative to positive, because the convention of positive to negative was established before we understood how electricity worked, so it stuck, even once we learned the truth.
Many circuits will use a convention of having a “ground” that is not the “earth” ground but rather the negative side of a direct current (DC) power source. It’s called “ground” in context but it’s not the same as “earth” ground, which can lead to confusion. Even worse, it can sometimes be tied to or referenced to “earth” ground, increasing confusion for people learning about this stuff.
In the case of the Arduino, it will supply a “ground” pin, that’s actually the negative terminal of the circuit, and isn’t really the same as “earth” ground. The current in a circuit directly driven by the Arduino, like an LED flasher or something, will go out the ground pin, through the circuit and into the positive pin.
If it is irritating to think of it this way (from negative to positive), feel free to turn it over in your head and use “conventional” current flow, from positive to negative- it doesn’t matter which way you think about it, as long as you’re consistent in applying it, the math works both ways, so in the end it’s not that important.
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