Ground (electronics) question

Well as far as I know, ground isn't the "output". Ground is...ground. We need something to compare all other potientals to, so we set one particular low one to "ground". Then we can define voltage as pot - groundpot (potiental).

Where you may have gotten the idea that ground is the output is that the output is usually across some wire and ground. That difference is the voltage output, I guess. A lot of circuits are that way. I'm going to go to sleep now, so I haven't really looked at your circuit. Hopefulyl I'm not wrong. Off i go..

Ground is a constant low electric potential, typically defined to be zero. In DC, the return path fits this definition. In AC, the direction of the current changes, and so the "return" path becomes the forward path, and so neither normal path fits this definition.

Yeah. Notice it's AC, so ground isn't actually part of the power supply. Ground will be grounded to something else, for example a metal case.

you know in a lot of electrical plugs you have 2 vertical slits and one circular one under them...? The ground is the circular one. The ground is connected to... you guessed it, the ground :). As far as I know, its usually connected to a metal component of the building your in. I think they actually put a ground in the building. But then again, my floating fairy leprechaun friend tells me im wrong

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See the ground connected to the arse-ends of diodes D1 and D3? I don't get the point of this one... surely current can't flow there no matter what, so what's it's point?

The four diodes form what is called a bridge rectifier. It's a circuit used to, in simplified terms, convert AC to DC. So the left part of the circuit is high voltage AC, the right part is low voltage DC. The ground on the right is simply the current return path, the commonly used "0 volts" ground. The ground on the left is the security grouding potential, decoupled with capacitors (to avoid high frequency noise on the circuit). The high voltage AC ground is mainly used as a security measure. If you touch a high voltage part of the circuit, some current will flow through your body to the ground. The electrical installation of your house is also grounded, that is the second pole. So, the current flowing through your body takes a different path than the usual second wire return path. This is called the residual current. A special security device (the residual current circuit breaker) will detect that current, will trigger a relay, and immediately cut the power supply to the circuit. The same system is used to prevent dangerous anomalies in your electrical installation - for example open wires touching the ground, badly insulated underground cables, etc.

Just connect all the ground symbols with each other and you have what the circuit really is.

The ground can for example be: the metal cage of the device, a ground plane in the PCB, ..., and usually all voltages in the circuit are measured against the ground potential (since you can only measure the difference between two potentials)

That is the oddest, least intuitively diagrammed bridge recitifier ever. EVER. But it is a bridge recitifier.

i think i seen more odder recitifiers....
edit:and that drawing like there are famous :-)
edit2:and to make it more odd,just re-draw diodes that are connected to ground connected to two separate ground simbols :) ...oh yes,also draw 'em in parallel with non-grounded diodes and it will be even more odd.

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Original post by Puzzler183 That is the oddest, least intuitively diagrammed bridge recitifier ever. EVER.

That's actually one of the standard diagrams for a bridge rectifier, besides the other well known tipped box one.

Ok, thanks a lot for all you help! I think I've got the gist of it now. I've seen bridge rectifiers before, but I didn't recognise this as one... it's clearer now though.


Thanks again!!

Think of ground as a common point in the circuit.