CircuitTheory.pptVIP

Circuit Theory What you will use this for Power management Signals between subsystems Possible analog data types How the knowledge will help you Understanding power and energy requirements Behavior of digital electric signals Analog signal conditioning and limitations Understanding associated technologies Circuit theory Topics Circuit Topology Voltage, Current and Power Kirchoff’s Laws Circuit components DC circuits AC circuits We will consistently use Systeme International d’Unites, or SI units here. Basic units are Meters[m], Kilograms[kg], Seconds[s], and Amperes[A]. Circuit Topology A circuit consists of a mesh of loops Represented as branches and nodes in an undirected graph. Circuit components reside in the branches Connectivity resides in the nodes Nodes represent wires Wires represent equipotentials Voltage, Current and Power (1) The concept of charge The Coulomb [C] – the SI unit of charge An electron carries -1.6e-19 [C] Conservation of charge The concept of potential Attraction/repulsion of charges The electric field The energy of moving a charge in a field Voltage, Current and Power (2) Voltage is a difference in electric potential always taken between two points. Absolute voltage is a nonsensical fiction. The concept of ground is also a (useful) fiction. It is a line integral of the force exerted by an electric field on a unit charge. Customarily represented by v or V. The SI unit is the Volt [V]. Voltage, Current and Power (3) Current is a movement of charge. It is the time derivative of charge passing through a circuit branch. Customarily represented by i or I. The SI unit is the Ampere [A]. Voltage, Current and Power (4) Power is the product of voltage by current. It is the time derivative of energy delivered to or extracted from a circuit branch. Customarily represented by P or W. The SI unit is the Watt [W]. Kirchoff’s Laws These laws add up to nothing! Yet they completely characterize circuit behavior. Kirchoff’s Voltage Law (KVL) - The sum of