Using a transformer to isolate a circuit means that any reference, e.g. ground, on the primary side no longer applies to the secondary side. Once this is done, by use of a transformer, you can ground any single point you wish to ground, on the secondary side of the transformer and circuit. The safety is increased because most electrical plugs can be reversed, so the incoming wire which may have initially been connected to ground, and to the chassis, will be connected to the "hot' (non-neutral or ungrounded) wire of the plug, when the plug is turned around. If this occurs then the chassis will be connected to 110 VAC (220 VAC in most of the world), resulting in a very unsafe, and potentially lethal, condition.
An isolated circuit means that the circuit has no path to ground.
Don't try this at home. It is only mental exercise.
Imagine this:
A rather large, 100V battery is sitting in a rubber box, on a metal floor.
If you stand on the metal floor, and touch only the positive terminal of the battery, nothing happens.
If you touch only the negative terminal of the battery, nothing happens
This is because there is no path to ground.
This is like accidentally touching one terminal, or the other, of the secondary side of an isolation tranformer.
If, however, the battery had one terminal connected to the metal floor, and a person touched the other terminal (while standing barefoot on the floor), the battery is no longer isolated, and they would experience a potentially fatal shock.
The same could happen if the secondary had one terminal (or the "center tap") connected to ground.
Means the whole circuit is isolated from outside AC power hot line by use transformer coupling. It is much safer for user even accident touching the circuit AC line from secondary winding without facing a danger shock through earth ground path.Because the transformer insulation layer prevent it happen.
It mean to isolate the circuit from ground, this can be done with a transformer if the secondary is not grounded
A transformer takes line line voltage from a outlet or source, and then gives out a voltage that is grounded and safer.
If you touched the outlet you'd be given a big shock with the full power of the incoming amps/voltage because it's not grounded, but you'd only get a ok shock from the voltage from the secondary winding because it's grounded and so wont have the full force of the line current with it.
Use a metal fork to test this, you'll see I'm right.
When you use a transformer and it isolates a circuit, what does that mean? And what are the safety advantages of it? How does it make it safer?
