Unit 3, Day 7-8 Kirchhoff’s Junction Rules Calculation of Circuit Currents using Kirchhoff’s Rules Circuit Analysis Approach

Kirchhoff’s Loop Rules Junction Loop Junction Rule: At any junction point, the sum of the currents entering the junction must equal the sum of the currents exiting the junction. Loop Rule: The sum of the voltages in any closed loop must add up to zero.

Calculation of Circuit Currents

Circuit Analysis Approach Define the currents and voltages in their expected directions Pick a junction & count the number of connections. In the case presented here, there are 3 connections at junction “d” n-number of connections at a junction requires n-equations to solve (in this case n = 3) Write 1 current junction equation, and (n-1) loop equations (in this case 2 loop equations). Write all loop equations in terms of the currents – using Ohm’s Law: V=IR Solve the simultaneous equations using substitution method, elimination method, or matrix method (using the TI-83)