PDA

View Full Version : calculation about dioide with ideal diode model method


adrian116
Sep29-07, 11:37 AM
1. The problem statement, all variables and given/known data

This problem is to find the I and V by ideal diode model method (assume there is no voltage drop and resistance within the diode)

2. Relevant equations

Just simple Ohm's Law equation

3. The attempt at a solution

First i assume the diode 2 is open, but i don't know how to calculate the equivalent resistance of the circuit? is that just all in series or R4+R2//R3+R1?

DefaultName
Oct3-07, 10:25 PM
I'm not sure what the V is referring to - remember the voltage is the difference in electric potential between TWO points, over an element.

Nodal analysis might be a good start.

pooface
Oct3-07, 11:34 PM
If the diode is ideal i.e. has no voltage drop across it then the diodes are effectively shorts if they are forward biased. Based on this information, redraw the circuit and work from there.

DefaultName
Oct4-07, 06:34 AM
The graph of an ideal diode looks like this:

http://physics.usask.ca/~angie/ep311/images/ideal_diode0001.jpg

which further reinforces what pooface said.

little ing.
Mar23-08, 05:40 AM
The problem is:
Find I current and potential V for this circuit!