PSpice with Mutual Inductance. Editing the Inductor Symbol. Using the K_Linear. EE230-Su05-Lecture 7 7 June by Henry L.

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1 EE230Su05Lecture 7 7 June 2005 PSpice with Mutual nductance nductor dotting Edit the symbol library Mutual inductance Use K_Linear Linear transformer Use XFRM_LNEAR deal transformer Use XFRM_NONLNEAR 2 Editing the nductor Symbol. Access the parts browser (CtrlG) 2. Select the inductor (Part L) 3. Press the Edit Symbol button 4. Add a circle to the left end t actually doesn t t matter, but this is consistent with the text s s examples 5. Save and close 3 Using the K_Linear Use the K_Linear part Specify Coupling (k value) nductors being coupled as L, L2, etc. Suggestions Name inductors without numbers Set the display as appropriate Watch the dots by Henry L. Welch

2 EE230Su05Lecture 7 7 June Sample Circuit Problem Transformers Linear Use XFRM_LNEAR Specify k, L, and L2 deal Use XFRM_NONLNEAR Specify k= Use large turn counts, but maintain ratios f necessary connect primary and secondary Use a large R value so PSpice has a reference 6 Two Port Networks One Port Networks Summarize end of a circuit e.g. Thevenin and Norton Equivalents Two Port Networks Two pairs of terminals by Henry L. Welch 2

3 EE230Su05Lecture 7 7 June Examples of Twoports Basic amplifiers Stereo amplifiers are four, or more, port networks Transformers Single phase with two windings Singlephase AC transmission lines Operational amplifiers 8 nput, Output, and Parameters oltage and Current at each set of terminals and are the inputs 2 and 2 are the outputs Four parameters summarize the circuit Six ways this is commonly done 9 Example Circuit by Henry L. Welch 3

4 EE230Su05Lecture 7 7 June Solve for the oltages Loop equations for and 2 Apply KL around each loop = 5 5( 2 ) 2 = 0 2 5( 2 ) Combine terms = = Find a General Form Four parameters needed Use mpedance opencircuit impedance parameters = z z = z 2 z 22 2 Put into matrix form z z2 = 2 z2 z Add Two Sources by Henry L. Welch 4

5 EE230Su05Lecture 7 7 June ndividual Elements OpenCircuit nput mpedance OpenCircuit Transfer mpedance to 2 OpenCircuit Transfer mpedance 2 to OpenCircuit Output mpedance z = 2 =0 z 2 = 2 =0 2 z 2= 2 =0 2 z 22 = 2 =0 4 Sample Circuit Revisited 2 2 Apply the new definitions 5 Example from Text 2 Ω Z := 6Ω 2 30 Z 2 := 4j Ω 2 Z 2 := 4jΩ Z 22 := 8Ω Caution: Answers in the book are wrong! by Henry L. Welch 5

6 EE230Su05Lecture 7 7 June Admittance Parameters Another way to parameterize a circuit nverse of the impedance parameters Also called the shortcircuit parameters Built from nodal analysis y y2 = 2 y2 y ndividual Elements ShortCircuit nput Admittance ShortCircuit Transfer Admittance to 2 ShortCircuit Transfer Admittance 2 to ShortCircuit Output Admittance y = =0 2 y 2 = 2 =0 2 y 2= =0 2 2 y 22 = 2 =0 8 Hybrid Parameters Z and Y parameters cannot always be computed e.g. deal Transformers Z and Y don t t often make much sense e.g. Amplifiers h h2 = 2 h2 h by Henry L. Welch 6

7 EE230Su05Lecture 7 7 June ndividual Elements ShortCircuit nput mpedance OpenCircuit Reverse oltage Gain ShortCircuit Forward Current Gain OpenCircuit Output Admittance h = =0 2 h 2 = 2 =0 2 h 2= =0 2 2 h 22 = 2 =0 20 Work Problem 2 2 Find the h parameters 2 nverse Hybrid Parameters and 2 are now the dependent variables Also defined as an inverse: g = h g g2 = g g by Henry L. Welch 7

8 EE230Su05Lecture 7 7 June ndividual Elements OpenCircuit nput Admittance ShortCircuit Reverse Current Gain OpenCircuit Forward oltage Gain ShortCircuit Output mpedance g = 2 =0 g 2 = 2 =0 2 g 2= 2 =0 2 g 22 = 2 =0 23 Transmission Parameters Used for transmission models e.g. AC power or communication Transmission through the network Have 2 point out from port two A B 2 = C D 2 24 ndividual Elements OpenCircuit oltage Ratio A= 2 2 =0 Negative ShortCircuit Transfer mpedance B= 2 =0 2 OpenCircuit Transfer Admittance Negative ShortCircuit Current Ratio C= D= 2 2 =0 2 = by Henry L. Welch 8

9 EE230Su05Lecture 7 7 June nverse Transmission Parameters Reverse the roll of the currents and voltages 2 a b = c d 2 26 ndividual Elements OpenCircuit oltage Gain 2 a= =0 2 Negative ShortCircuit Transfer mpedance b= =0 OpenCircuit Transfer Admittance Negative ShortCircuit Current Gain 2 c= 2 d= =0 =0 27 Equivalent Circuits () by Henry L. Welch 9

10 EE230Su05Lecture 7 7 June Equivalent Circuits (2) 29 Parameter Conversions All 6 forms are interchangeable Use the form that makes the most sense See summary in the text or on the web 30 Reciprocal Networks Only linear elements No dependent sources Look for parameter patterns z 2 = z 2 h 2 = h 2 ADBC = ad bc = by Henry L. Welch 0