Measures of regulator quality:

The output voltage can just be held roughly constant; the regulation is fixed by two measurements:

1. Load regulation is the alteration in output voltage for a specific change in load current (for instance: "usually 15mV, maximum 100mV for load currents between 5mA and 1.4A, at some fixed temperature and input voltage").

2. line regulation or input regulation is the degree for which output voltage alters with input (supply) voltage changes - as a ratio of output to input change (for instance "typically 13mV/V"), or the output voltage alter over the entire fixed input voltage range (for example "plus or minus 2% for input voltages among the 90V and 260V, 50-60Hz").