Linear Circuits 1 - 03 - Current Sources

Explore current sources and apply ohm's law to solve circuits, building on voltage source fundamentals and showing that ground location does not affect voltage drops.

Current sources have one job: maintain a fixed current regardless of voltage, shown by an arrow, e.g., one amp up or negative three amps, where sign changes reverse direction.

Learn how positive and negative current signs indicate direction, with examples showing left-to-right or right-to-left flow, and that changing signs reverses direction.

A two-amp current source drives current through a tandem resistor, producing a 20-volt drop, while lecture shows how current flows from high to low potential and Delta V orientation matters.

Identify an arbitrary ground node; current sources fix magnitude and direction of current. Three amperes flow through the 5-ohm resistor, yielding a 15-volt delta v (positive).

Compare two copies of the same circuit with different ground locations to show ground is arbitrary; a four-amp current flows through the 1-ohm resistor, yielding a four-volt drop in both.

Explore how negative current sources operate in circuits with two different grounds, apply Ohm's law to a five ohm resistor, and determine delta V orientation and resulting current directions.

Explore circuits with multiple current sources, establish a ground, and use Ohm's law to find a +10 volts at the top of a two-ohm resistor when five amps flow.

Identify the ground reference, track node currents from three current sources, and apply Ohm’s law to determine a 28-volt delta across the seventh resistor and the positive delta V terminal.

Discover why placing current sources in series is problematic: two sources forcing different currents fight each other, potentially damaging the sources and breaking the circuit.

Recognize that current sources have a single job, and apply Ohm's law: delta v equals i times r with current entering the positive terminal on the schematic.