Positive or Negative to Battery switch

TxTwoSome wrote:
Ok ask yourself which way would Clark Griswold wire his?

Everyone knows he is a MASTER ELECTRICIAN:B

He's in food preservatives. You're thinking of Jack Butler

6 pages of answers, and we still don't know.

Ok ask yourself which way would Clark Griswold wire his?

Everyone knows he is a MASTER ELECTRICIAN:B

LittleBill wrote:

joshuajim wrote:
Perhaps this will enlighten some folks.

Here

the person who wrote that document should be fired, you need 2 wires to complete a circuit, both sides of the circuit will use the same amount of power. PERIOD.

NPN transistors are primarily used for ground switching as they are not dependent on the voltage of the circuit they are powering, but are able to use the voltage of the micro controller, generally a 3.3v or 5v reference voltage, where as PNP transistors are switched on the positive side and must match that of the circuit they are powering.

i really didn't want to go into that. needless to say everything i said in regards to switching the power on either side changes nothing in regards to arching or amp usage, the general reason they switch ground is the reason i listed above

Yep.


The only thing I'll give the author of that so-called "technical" article is that there is a lower chance of a shorted wire on a load causing maximum AMPS to flow through the computer control transistor if you switch the ground. To do that would mean the wiring shorted to a +12V source. If the +12V side were switched, the wire need only find a ground to short to of which there are plenty on a grounded frame vehicle. Either way, a properly designed system will have fuses that blow before the wiring or control box.

That said, none of this has to do with disconnecting a battery on a trailer.

joshuajim wrote:
Hmmm... nice spin.

your right, my head is spinning...

Hmmm... nice spin.

SCVJeff wrote:

joshuajim wrote:
Perhaps you gentlemen need to reread the article instead of shooting from the hip, You would have noted that the computer SWITCHES the NEGATIVE on the power module which connected to the positive load and ground. The computer DOES NOT handle any power itself, it just does the switching (on the negative!)

I think any of us electronics engineers and techs here are fully aware of how a control system works. Perhaps you should reread the entire thread as to what we are complaining about.

and understand how the circuit actually works based on his comments i don't think he really does. which like i said early has nothing to do with the OP

joshuajim wrote:
Perhaps you gentlemen need to reread the article instead of shooting from the hip, You would have noted that the computer SWITCHES the NEGATIVE on the power module which connected to the positive load and ground. The computer DOES NOT handle any power itself, it just does the switching (on the negative!)

I think any of us electronics engineers and techs here are fully aware of how a control system works. Perhaps you should reread the entire thread as to what we are complaining about.

Perhaps you gentlemen need to reread the article instead of shooting from the hip, You would have noted that the computer SWITCHES the NEGATIVE on the power module which connected to the positive load and ground. The computer DOES NOT handle any power itself, it just does the switching (on the negative!)

Yeah but if some idiot wrote it on the internet it must be true...