Source

• A device that converts non-electric energy into electrical energy
• Ideal source: Delivers or absorbs power at a relatively fixed voltage or current

(In)Dependence

• Independent
  • Do not rely on anything in the circuit
  • A constant voltage or current will be output no matter the load
  • Notated with a circle
• Dependent
  • Depends on another voltage or current in the circuit
  • Notated with a diamond
  • When multiplying by a constant
    • Voltage controlled by voltage: $\mu$
    • Voltage controlled by current: $\rho$
    • Current controlled by voltage: $\alpha$
    • Current controlled by current: $\beta$