I'm experimenting with an Arduino, I feel like it's a good "getting your hands dirty" device when it comes to learning electronics. Before I dive into it, I'd like to know some of the underlying concepts of electronic devices. I've been reading articles, posts and watching YouTube videos in my spare time this week about electronics.
Although, I'm still not certain what is meant when people say current will want to flow or go to ground?
I've got a vague understanding what ground is. The ground is an abundant source of electrons with zero voltage(or close to) i.e. it is said to be an area of zero potential. Plugs in the UK have a third pin which one wire is connected to ground, this wire is touching the metal casing of an electronic device such as a washing machine, if a wire was to come loose and hit the metal, the current would flow through you. This ground pin prevents situations like this.
Arduinos', other microcontrollers and integrated circuits have ground pins, this pin gets it's name from the ground(zero potential) and is just a reference point for measuring voltage.
With that said, I'm still uncertain what is meant by current wanting to flow to ground...
To illustrate further, let's take a simple closed circuit, one containing a battery for the power/voltage, a copper wire and a light bulb. The positive(+) end of the battery demands electrons, whilst the bottom end(negative terminal) builds up a surplus of electrons that are "pushed" out of the negative end to the atoms of the copper wire.
People say that the negative end of the battery is ground, i.e. 0 volts or the the low potential measuring point BUT.. When people say that current always wants to return to ground, it's returning to the positive terminal and not the negative terminal??? It makes sense that the positive terminal is the part of the battery that's creating the push by demanding extra electrons but again, if people say the current wants to return to ground then why is the current going to the positive terminal and not the negative terminal???
There's probably something simple that is catching me out, I'll postface by saying, I'm still green when it comes to electronics and when I say extremely, I emphasize that, if someone could try explain it in a beginner friendly way as possible would really be appreciated :)
Warning: if you do not understand ground, you are likely to damage something if you are hooking up wires or fooling with electricity at the wire level.
That said, there should be a line through your setup that is 'ground' which represents the 'earth' in a more classical electrical setting. For example in 1955 your TV antenna would have a wire running off it that was literally buried in the ground so if it got hit by lightning, it would take that path rather than go hunting for ground by way of your TV, which would not survive.
Ground is representing that: its a place for excess positive electricity to go, in the simplest way I can think to say it. Sure, your electricity also goes positive to negative, and for small things, often the negative terminal is sufficient to play 'ground' in the setup (like a flashlight, thats all you got) but on something like a boat, for example, there is a metal slab down in the water that lets lightning or excess power (from whatever source) bleed off safely, and on your car, the metal frame is treated as ground. Another example, the 3rd hole of an outlet in the USA is ground. The other 2 alternate, being AC current. By the time you are at electronics, you are usually in DC, converted from AC or from a battery is irrelevant.
last time I did embedded stuff, there was a ground clearly indicated in the system and you just connect to it as needed. There can even be more than 1, and often there are many, many places to connect to it for easy access. Those all share one tie in to the actual ground that runs off to a piece of metal or something, be sure that gets connected properly.
I don't really see the point in anthropomorphizing the battery. The battery doesn't "demand" anything. Any analogy is going to be imperfect, but perhaps you can think of voltage as pressure. Just as an area of high pressure will try to equalize if given a place to flow, the high pressure at the (+) end of the battery will flow to an area of lower pressure (-) if allowed to.
Voltage is a difference between two points, so ground is a just a reference point that every other voltage can be compared against.
Also, electrons are just an implementation detail. You don't need to know what an electron is to understand circuits. (We were making electronic circuits before we knew what an electron really was, hence why we got the positive vs. negative thing backwards.)
He says a cars' chasis can be be used a ground or a common, the current can flow through the chasis back to the negative terminal of the battery, this makes sense in terms of using a chasis as ground, obviously ground is a path for the current to get back to the other terminal and complete the circuit,but..... I thought the current will flow to the positive terminal?? i.e electrons will be attracted to the positive terminal as this is the terminal that demands extra electrons such as a 12v battery.
I think that was just a minor error from whoever made that diagram. AIUI, electrons do indeed flow from the negative terminal to the positive terminal of a battery. However, within the context the direction of the flow of current is not relevant. The point is how the components of the circuit are connected, and that the chassis is being used as a common return path (or as a common out path, depending on how you look at it). As long as you keep that idea consistent and don't create a short-circuit, for example by connecting both sides of a component to ground, the direction doesn't really matter.
The terms bandied about are earth, ground and common (and sometimes common ground, frame/chassis ground etc). Depending upon how these terms are used, they may or may not mean the same. But in general common is not earth and ground may or may not mean earth. This terminology is IMO widely miss-used with different authors/designers meaning different things by the words. Chassis ground and earth ground have different symbols (but are often interchanged!).