Ideal voltage sources Voltage source

the internal resistance of ideal voltage source zero; able supply or absorb amount of current. current through ideal voltage source determined external circuit. when connected open circuit, there 0 current , 0 power. when connected load resistance, current through source approaches infinity load resistance approaches 0 (a short circuit). thus, ideal voltage source can supply unlimited power.

no real voltage source ideal; have non-zero effective internal resistance, , none can supply unlimited current. however, internal resistance of real voltage source modeled in linear circuit analysis combining non-zero resistance in series ideal voltage source (a thévenin equivalent circuit).

a near ideal voltage source has been contemplated balanced post office box (po box) network consisting of 4 diodes sourced balanced supply centre tapped transformer , capacitive filter ground open creating positive , negative alternating reference level. if 1 of points of equal potential of balanced po box supplied non ideal voltage source other point ( opposite ) raise same potential @ virtual ground condition , raised voltage @ point of virtual ground creates ideal constant voltage source. ideal constant current source, ideal constant voltage source causes 0 power supplied load, hence reflection load source minimum causes better representation of waveform.