Thevenin's Theorem: Simplifying Complex Circuits with Equivalent Circuits, Slides of Digital Logic Design and Programming

Download Thevenin's Theorem: Simplifying Complex Circuits with Equivalent Circuits and more Slides Digital Logic Design and Programming in PDF only on Docsity! Thevenin’s Theorem – Thevenin’s theorem simplifies the process of  solving for the unknown values of voltage and  current in a network by reducing the network to  an equivalent series circuit connected to any pair  of network terminals. – Any network with two open terminals can be  replaced by a single voltage source (VTH) and a  series resistance (RTH) connected to the open  terminals.  A component can be removed to  produce the open terminals. docsity.com Thevenin’s Theorem R,=30 R,=30 A V= = Re Short R, 36 V 6a across 60 feat V B (a) (b) (c) Fig. Application of Thevenin’s theorem. (a) Actual circuit with terminals A and B across R,. (b) Disconnect R, to find that V,, is 24V. (c) Short-circuit V to find that Ry, is 20. ® docsity.com Thevenin’s Theorem R,=30 A,=40 Ary =6 0 (b) (c) (a) Vy, is still 24V. (b) Now the R,, is 2 + 4 = 6Q. (c) Thevenin equivalent circuit. ® docsity.com Thevenizing a Circuit with Two Voltage Sources Let,s find the current through R3 by thevenizing the entire circuit except R3 Ry Ro 122 4Q a Aas t. a 30V—— 66 = 26V of Ry 12 ASS : +3v— l 300 = ETH wary Cc Ry Re 12Q 4Q +3 — EV — ayaeebe 3V 1V Slee = = £2 B 30v_> Ss R3 = _26v Re ag Ww a tive Ety > 27V =e 5 re D RTHE 32 -——-~~ ETH" ee ERS 27V , 6a F docsity.com Thevenizing a Circuit  with Two Voltage  Sources Steps: • Disconnect R3 from the circuit • Since E1 and E2 oppose each  other , the net voltage is  E1 – E2 = 30V – 26V = 4V • Total Resistance is R1 + R2 = 12 + 4 = 16 ohm • Thus, current is    4V /16 ohm = 0.25 A (CCW) • ER1 = 0.25  x 12 = 3V and ER2 = 0.25 x 4 =1V docsity.com Steps: • Now voltage between   a&b is    20 – 4  = 24 V (left) • Also the same                  28‐4 =  24 (right) • Rth = R1 // R2 = 4 ohm • Reconnect R3 and find  current  E/Rt = 24V / 12 ohm = 2A docsity.com Thevenizing a Circuit  with Two Voltage Sources Fig. Thevenizing a circuit with two voltage sources V1 and V2. (a) Original circuit with terminals A and B  across the middle resistor R3. (b) Disconnect R3 to find that VAB is −33.6V. (c) Short‐circuit V1 and V2 to find  that RAB is 2.4 Ω. (d) Thevenin equivalent with RL reconnected to terminals A and B. Example: docsity.com