1-port Thvenins theorem Apply a voltage and measure the current. - PowerPoint PPT Presentation

Coping with complexity in Coping with complexity in engineering design: engineering design: Computer language models Circuit language models • Primitives • Primitives – primitive data, primitive procedures – resistor, voltage source • Means of combination • Means of combination – functional composition, data structures – wire things together at nodes • Means of abstraction • Means of abstraction – procedure definition, data abstraction – ??? • Capturing common patterns • Capturing common patterns – Higher-order procedures, objects, classes 1-port Thévenin’s theorem Apply a voltage and measure the current. Any two-terminal network The 1-port is made up of resistors and completely described voltage sources, when by the relation of the viewed from the between the voltage terminals, is completely and the current. It electrically equivalent to doesn’t matter what’s a network composed of a in the box, so long as single resistor and a the relation holds. single voltage source. Analogy: An abstract data type is described by its API.

Step 1: The voltage V TH is the voltage we’d see at the terminals Example: From the Wikipedia Step 2: The resistance R TH is the resistance we’d see at the terminals (when we set the independent source to zero). The voltage at the terminals is 7.5V, so V TH is 7.5V

Coping with complexity in engineering design: Circuit language models • Primitives – resistor, voltage source • Means of combination – wire things together at nodes • Means of abstraction – 1-ports (Thévenin equivalence) • Capturing common patterns The resistance seen from the terminals is 2k � , so R TH is 2k � Ideal op-amp model 1-port 2-port … and in general, n-ports K might be around 10,000

Ideal op-amp model Non-inverting amplifier K might be around 10,000 Coping with complexity in engineering design: Circuit language models • Primitives – resistor, voltage source • Means of combination – wire things together at nodes • Means of abstraction – 1-ports (Thévenin equivalence), n-ports • Some common patterns – feedback