Abstract: When performing interleaved switching, a power generation system may include chokes for filtering out a high-frequency ripple. However, because the chokes are interconnected, a common mode current can flow between the different parallel converters. Instead of connecting all the outputs of a parallel converter to the same choke, the same phase of each of the parallel converters is sent to one of the chokes. For example, the first phase signals are sent to a first choke, the second phase signals are sent to a second choke, and so forth. By doing so, air gaps in the chokes can be manipulated in order to provide a different inductance for the common mode current than a grid current. For example, the air gaps may be arranged such that the inductance corresponding to the common mode current is greater than the inductance corresponding to the grid current.

Abstract: A multi-mode microwave heating device includes a heating chamber, a plurality of microwave transmitters, a plurality of longitudinal-polarized rectangular waveguides, a plurality of transverse-polarized rectangular waveguides, and a plurality of half-wave-rectified power supplies. The heating chamber has a holder for holding a to-be-heated object. The holder is connected to a rotating and an elevating mechanism. The microwave transmitters are connected to the heating chamber through the longitudinal-polarized rectangular waveguides as well as connected to the transverse-polarized rectangular waveguides for transmitting microwaves into the heating chamber and to excite multiple cavity modes of the heating chamber, so as to achieve uniform microwave heating.

Abstract: An LED-based lighting apparatus is powered by multi-phase AC voltages to reduce flicker. A multi-phase AC-to-AC power generator is used to generate a plurality of AC voltages from an AC power source. The plurality of AC voltages each having a different phase are rectified by a plurality of rectifiers to provide a plurality of rectified AC voltages for a plurality of LED lighting units. Each LED lighting unit has voltage dependent brightness and reaches maximum brightness at different time due to the phase difference in the rectified AC voltage. The peak-to-peak variation in the total brightness is reduced and therefore the LED-based lighting apparatus has low flicker.

Abstract: A power supply system for portable floodlighting equipment employing high-intensity electric discharge lamps comprises an alternating current generator having three or more independent armature windings, one for producing independently current at a voltage sufficiently high for starting a discharge lamp in series with a capacitor. The windings are out of phase with one another and interference with the operation of the lamps energized by the separate and independent windings and electric apparatus energized by the standard voltage generator is effectively eliminated. The use of the generator winding for starting and energizing the lamps eliminates the usual starting ballast and decreases the weight and cost of the portable floodlighting unit.