Microsecond - 1,000,000th of a second (mS).
Charger - Device associated with the rectifier and used to supply the battery with the electrical power (DC current) required to recharge and/or float charge the battery, thus ensuring the rated backup time.
Brownout - A steady state RMS voltage under nominal by relatively constant percentage.
Power factor (l) - Ratio between the active power P supplied to a load and the apparent power S supplied to said load by an AC power supply.
Inverter (off-line or stand-by) - UPS configuration in which the inverter is parallel-mounted to the load supply line and backs up the mains. This configuration offers a substantial cost reduction but is applicable only to low outputs, under 3 kVA, because it results in an interruption lasting up to 10 ms during transfer and does not filter inrush currents.
Harmonic Sinusoidal - Term of the Fourier series expansion of a periodic function. The harmonic (or harmonic component) of the nth order is characterized by - Yn is the rms value of the given harmonic component, w is the angular frequency of the fundamental, related to frequency by - w = 2_f; phin is the phase angle of the given harmonic component at t = 0.
Intermittent Test - A test during which a battery is subjected to alternate periods of discharge and rest according to a specified discharge regime.