question for EE majors

[cheapgoose]

considering how I slept through my EE98 last semester, I'm kinda unsure of the answer to the following question.

so in a circuit, current will flow through the path with less resistance. right?

so I'm thinking, instead of making a conventional 12v-off-7v switch for my fan,

what if, I hook up my fan in the 7v mode, + to 12v, and- to 5v, then put in parallel - to ground with a spst switch.

so when the switch is closed, current goes through the 5v as ground, but when the switch is open, current will go through the switch because it's connected to ground.

am I crazy ?

 

[syberscott]

Not really an EE question, but whatever. 😉
To answer your question, yes you are crazy. This would short out the 5 volt line.

 

[cheapgoose]

Originally posted by: syberscott
Not really an EE question, but whatever. 😉
To answer your question, yes you are crazy. This would short out the 5 volt line.

I don't get it, shouldn't there be no current out of the 5v line, there's no load between the 5v and ground.

 

[syberscott]

Correct, there is no load between them, but when the switch is closed the 5 volt line and ground would be connected. And with no resistance it will take as much current as the PS will put out until something melts.
And BTW, you have the terms open and closed mixed up in your first post.

 

[cheapgoose]

Originally posted by: syberscott
Correct, there is no load between them, but when the switch is closed the 5 volt line and ground would be connected. And with no resistance it will take as much current as the PS will put out until something melts.

oh doh! yea, you're totally right. I guess I should've paid more attention. thanks again.