Switch position

[Stamf]

G'day,

I was wondering if there are any advantages / disadvantages of placing a switch in a circuit on the positive or negative side of the load? In my mind having the switch on the positive side makes sense since there would be no voltage source as seen by the load and thus no easy way to accidentally power it, but I have seen some circuits where switches are used specifically on the negative side..

So yeah, am I just imagining things here or is there no difference? Thanks!

 

[akg]

G'day,

I was wondering if there are any advantages / disadvantages of placing a switch in a circuit on the positive or negative side of the load? In my mind having the switch on the positive side makes sense since there would be no voltage source as seen by the load and thus no easy way to accidentally power it, but I have seen some circuits where switches are used specifically on the negative side..

So yeah, am I just imagining things here or is there no difference? Thanks!

in most of the cases it will not cause any difference. but in high voltage ckts switches are on both lines. and if u can, pls post the ckt that has specific sw: on gnd.

 

[Stamf]

I don't have any schematics of them but I've seen some home light bulb circuits that use a ground side switch, could it be a safety issue at all?

 

[akg]

I don't have any schematics of them but I've seen some home light bulb circuits that use a ground side switch, could it be a safety issue at all?

it seems to be .. a safety precaution

 

[Nigel Goodwin]

Obviously it depends on the exact application, but electrically there's no difference at all. For mains switching you would normally switch the live wire, as switching the neutral would leave the appliance all live when switched off.

In a car you switch the +ve feed, as the chassis is connected to -ve, and (just as with mains switching) switching the chassis connection would leave the unit permantly live.