Warm-up Drift The initial change in output voltage of a power supply from turn-on until it reaches thermal equilibrium at nominal line, full load, ambient temperature.
Warm-up Time The time required after initial turn on for a power supply to achieve compliance to its performance specifications.
Wattage This is a form of power measurement. For AC power systems, the watts rating is the volts rating multiplied by the amps rating multiplied by the POWER FACTOR. Watts represent actual delivered energy. In a typical AC power system, some of the Amps delivered to the load do not deliver energy to the load.