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.
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Negative ground is a choice. It’s pretty common in cars, but not at all common in other products.
A negative terminal can terminate into ground via a switch, but the negative terminal of a circuit is not the same as ground.
Think of electricity like water.
To create a complete circuit with a battery you are creating a channel through which water can travel in a circle from origin back around to origin.
The positive terminal is where the water flows **in** to the channel. The negative terminal is where the water complete its run around the channel and flows back into the source point.
A ground would be like opening a spigot to let the water run out from the channel onto the ground itself, without completing the run around the channel provided.
The “ground” must always be placed between the pos and neg terminals in order to provide a relief point for the circuit. Once ground is utilized, energy no longer travels to the neg terminal.
In an electrical circuit the ground is active when a fuse trips or a switch is actuated. Without a ground point if the circuit is broken somehow the live energy will continually flow in a manner trying to reach the neg terminal. If this occurs, failure and possibly fire could result.
Assuming you’re talking about cars negative and ground are essentially the same thing. Pretty much anything other than cars and it’s very much not
On a car, yes. The negative terminal does connect to the car body/chassis so any electronics can also connect to the body/chassis to complete the circuit without running a separate ground cable. Sometimes there is a separate ground cable, but it might even be shared between different things
Not necessarily but, by convention, generally yes. Ground is nothing more than a baseline reference for all the voltages on a circuit. You start with whatever voltage your power source provides and call negative to the 0V pole and positive to +24V (or whatever) pole. Ground is always 0V so ground, negative and 0V all mean the same.
“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.
People are overexplaing this if you’re just asking for Arduino projects. Yes, connect everything ground/negative to a single point and to the ground pin.
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