# Branch Current Method... EF or CF?

Discussion in 'Homework Help' started by Thompson, May 19, 2008.

1. ### Thompson Thread Starter New Member

May 19, 2008
4
0
Does the branch current method outlined in chapter 10 use electron flow or conventional flow when mapping out the direction of the currents? You would think electron flow because the text states it uses electron flow but I found evidence that suggest otherwise. Using a circuit simulator (http://www.alternate-energy.net/aps/circuit_simulator05.html) to simulate a few circuits, it seems that all current directions are under conventional flow when using this method. If someone could clarify this matter for me I would appreciate it.

2. ### mentaaal Senior Member

Oct 17, 2005
451
0
Hi thompson, the direction of current flow you decide to take is entirely arbitrary for the purposes of using the branch current method. Just be sure to be consistant in the direction you choose. Of course as you know conventional current is just that, convention whereas actual electron flow is from the negative terminal of a battery to the positive.

3. ### Thompson Thread Starter New Member

May 19, 2008
4
0
I appreciate your response but I'm not sure it answers my question. Does the method use electron or conventional flow? If either, how do you switch between the two? When you have a circuit with one power source it's easy to see what direction the current is going (using electron or conventional). However, when you have multiple sources, like the examples in that section it's not easy to see which source actually has current forced through it backwards. This is why I ask, so I could see which battery(s) is over powering others.

4. ### Thompson Thread Starter New Member

May 19, 2008
4
0

This is what caused me to question this. This simulation from the bottom circuit looks like it uses conventional flow. In the circuit at the top, when I worked it out, I got current directions that were the same as the simulator. This leads me to believe that the method uses conventional flow rather than electron flow. So the actual current flow (electron flow) would be opposite of what I came up with using the method. Is this correct?

5. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
6
The simulator applet uses conventional current flow. The branch current method of analysis can use either. Just make sure you are consistent within a given analysis problem and you'll be fine.

6. ### JoeJester AAC Fanatic!

Apr 26, 2005
3,403
1,227
Just pick one and use it consistently.

I use electron flow. Conventional or Electron current flow never came to my mind when I was hung up on a 900 volt 300mA supply for about two-three seconds. It seemed like forever and I didn't do any emperical studies on the flow direction.

Last edited: May 19, 2008
7. ### Thompson Thread Starter New Member

May 19, 2008
4
0
Ok thanks you guys. That cleared things up a bit. I know the question seems a bit trivial as it doesn't really matter what direction the current is really going but it was something that spiked my curiosity. I'm guessing if you were to use electron flow using this method you would attribute a positive voltage going from + to -?

8. ### JoeJester AAC Fanatic!

Apr 26, 2005
3,403
1,227
I usually mark on the circuit where I'd place the neg probe and the positive probe of the multimeter. That way you can keep things straight.

If your using electron flow, the neg probe goes to the most negative point of the desired measurement.

Mar 20, 2007
1,068
3