1 / 21

SERIES PARALLEL RESISTOR COMBINATIONS

SERIES COMBINATIONS. PARALLEL COMBINATION. SERIES PARALLEL RESISTOR COMBINATIONS. UP TO NOW WE HAVE STUDIED CIRCUITS THAT CAN BE ANALYZED WITH ONE APPLICATION OF KVL(SINGLE LOOP) OR KCL(SINGLE NODE-PAIR). WE HAVE ALSO SEEN THAT IN SOME SITUATIONS IT IS ADVANTAGEOUS TO COMBINE RESISTORS

cooper-allison
Download Presentation

SERIES PARALLEL RESISTOR COMBINATIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SERIES COMBINATIONS PARALLEL COMBINATION SERIES PARALLEL RESISTOR COMBINATIONS UP TO NOW WE HAVE STUDIED CIRCUITS THAT CAN BE ANALYZED WITH ONE APPLICATION OF KVL(SINGLE LOOP) OR KCL(SINGLE NODE-PAIR) WE HAVE ALSO SEEN THAT IN SOME SITUATIONS IT IS ADVANTAGEOUS TO COMBINE RESISTORS TO SIMPLIFY THE ANALYSIS OF A CIRCUIT NOW WE EXAMINE SOME MORE COMPLEX CIRCUITS WHERE WE CAN SIMPLIFY THE ANALYSIS USING THE TECHNIQUE OF COMBINING RESISTORS… … PLUS THE USE OF OHM’S LAW

  2. FIRST WE PRACTICE COMBINING RESISTORS SERIES 6k||3k (10K,2K)SERIES

  3. If things get confusing…

  4. EXAMPLES COMBINATION SERIES-PARALLEL If the drawing gets confusing… Redraw the reduced circuit and start again RESISTORS ARE IN SERIES IF THEY CARRY EXACTLY THE SAME CURRENT RESISTORS ARE IN PARALLEL IF THEY ARE CONNECTED EXACTLY BETWEEN THE SAME TWO NODES

  5. AN “INVERSE SERIES PARALLEL COMBINATION” Given the final value Find a proper combination SIMPLE CASE NOT SO SIMPLE CASE

  6. EFFECT OF RESISTOR TOLERANCE RANGES FOR CURRENT AND POWER? THE RANGES FOR CURRENT AND POWER ARE DETERMINED BY THE TOLERANCE BUT THE PERCENTAGE OF CHANGE MAY BE DIFFERENT FROM THE PERCENTAGE OF TOLERANCE. THE RANGES MAY NOT EVEN BE SYMMETRIC

  7. CIRCUIT WITH SERIES-PARALLEL RESISTOR COMBINATIONS THE COMBINATION OF COMPONENTS CAN REDUCE THE COMPLEXITY OF A CIRCUIT AND RENDER IT SUITABLE FOR ANALYSIS USING THE BASIC TOOLS DEVELOPED SO FAR. COMBINING RESISTORS IN SERIES ELIMINATES ONE NODE FROM THE CIRCUIT. COMBINING RESISTORS IN PARALLEL ELIMINATES ONE LOOP FROM THE CIRCUIT • GENERAL STRATEGY: • REDUCE COMPLEXITY UNTIL THE CIRCUIT • BECOMES SIMPLE ENOUGH TO ANALYZE. • USE DATA FROM SIMPLIFIED CIRCUIT TO • COMPUTE DESIRED VARIABLES IN ORIGINAL • CIRCUIT - HENCE ONE MUST KEEP TRACK • OF ANY RELATIONSHIP BETWEEN VARIABLES

  8. …OTHER OPTIONS... FIRST REDUCE IT TO A SINGLE LOOP CIRCUIT SECOND: “BACKTRACK” USING KVL, KCL OHM’S

  9. LEARNING BY DOING

  10. AN EXAMPLE OF “BACKTRACKING” A STRATEGY. ALWAYS ASK: “WHAT ELSE CAN I COMPUTE?”

  11. SERIES PARALLEL THIS IS AN INVERSE PROBLEM WHAT CAN BE COMPUTED?

  12. THEN THE CIRCUIT WOULD BECOME LIKE THIS AND BE AMENABLE TO SERIES PARALLEL TRANSFORMATIONS IF INSTEAD OF THIS WE COULD HAVE THIS THIS CIRCUIT HAS NO RESISTOR IN SERIES OR PARALLEL Ra+(Rc+R4)||(Rb+R5)

  13. REPLACE IN THE THIRD AND SOLVE FOR R1 SUBTRACT THE FIRST TWO THEN ADD TO THE THIRD TO GET Ra

  14. DELTA CONNECTION LEARNING EXAMPLE: APPLICATION OF WYE-DELTA TRANSFORMATION ONE COULD ALSO USE A WYE - DELTA TRANSFORMATION ...

  15. CONVERT THIS Y INTO A DELTA? SHOULD KEEP THESE TWO NODES! IF WE CONVERT TO Y INTO A DELTA THERE ARE SERIES PARALLEL REDUCTIONS! LEARNING EXAMPLE THE RESULTING CIRCUIT IS A CURRENT DIVIDER

  16. NOTICE THAT BY KEEPING THE FRACTION WE PRESERVE FULL NUMERICAL ACCURACY WYE DELTA CIRCUIT AFTER PARALLEL RESISTOR REDUCTION

  17. SMALLER RESISTANCE FOR HIGHER POWER MEDIUM OR LOW HIGH

  18. This is the set up in the car Circuit Representation WHEN THE STARTER IS ENGAGED THE VOLTAGE DROP ACROSS THE RESISTENCE INCREASES 100 FOLD --- LIGHTS DIM!

  19. APPPLICATIONS Balance condition For bridge circuit Measure R3 with scale empty Measure R3 when truck is on sclae Weight is determined in the following manner. The change in R3 required to balance the bridge represents the change in strain, which when multiplied by the modulus of elasticity yields the change in stress. The change in stress multiplied by the cross-sectional area of the cylinder produces the change in load, which determines the weight

  20. Highest V2: No lamp connected Lowest V2: All lamps ON (5 lamps in parallel with R2) Equivalent circuit

  21. More realistic model – I_signal is NOT I_sensor. There is a current division determined by Rs and R_wire (length of wire becomes important) DESIGNS Design a current-to-voltage converter that will output 5 V when the current signal Is 20mA Assume that the controller does not use any current from the I to V converter. In this case a simple resistor behaves as current to voltage converter! Wire resistance does not matter! (within reasonable limits)

More Related