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US 6,324,078 B1Granted
Power source device
AssigneeMatsushita Electric Works, Ltd.
InventorsMasahiro Naruo, Takashi Kanda, Masahito Ohnishi, Kazuhiro Hori, Kazuo Yoshida
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AssigneeMatsushita Electric Works, Ltd.
InventorsMasahiro Naruo, Takashi Kanda, Masahito Ohnishi, Kazuhiro Hori, Kazuo Yoshida
Estimating the term…
A power source device includes a control circuit which controls switching elements in full-bridge arrangement so as, in decreasing an output to a load, to substantially equalize ON timing of one of two switching elements at diagonal position to the other of them with ON period of the one switching element shortened, that is, with ON duty ratio of the one switching element decreased. Switching operation of the elements in this event is not made to be in the hard switching operation, and a range in which the output to load can be controlled without increasing any stress or noise is thereby broadened, whereby it is enabled to minimize varying width of switching frequency and to attain a wide range control of the output to load without causing any one of the switching elements to be in the hard switching operation.
A power source device wherein two series circuits respectively of two switching elements are connected in parallel to a smoothing capacitor, a resonance circuit comprising at least an LC resonance circuit and a load is connected between both junction points of the switching elements in each of the two parallel circuits, a series circuit of a rectifying circuit for rectifying a source power from power source and an inductor is connected across one optional switching element in the two series circuits to employ the optional switching element as a chopper-common switching element performing a switching operation which causes a chopper circuit operation enabled, and a chopper diode is connected in inverse parallel to the other switching element series connected to the chopper-common switching element, characterized in that all switching elements are operated substantially at an equal switching frequency while respective switching elements in each series circuit are alternately turned ON and OFF, a timing of turning ON of the switching element in one of the two series circuits and connected to a low potential side of the smoothing capacitor is substantially equalized to a timing of turning ON of one switching element in the other series circuit and connected to a high potential side of the smoothing capacitor, and an ON duty ratio of at least one of the switching elements substantially equalized in the turning ON timing is reduced to lower an output to the load.
A power source device wherein two series circuits respectively of two switching elements are connected in parallel to a smoothing capacitor, a resonance circuit comprising at least an LC resonance circuit and a load is connected between both junction points of the switching elements in each of the two parallel circuits, a circuit of series connection of two rectifying diodes is connected in parallel across the smoothing capacitor, and a series circuit of at least power source and an inductor is connected between both junction points of the two rectifying diodes and of the switching elements in one of the series circuits so that the switching elements in the one series circuit are operated as chopper-common switching elements performing a chopper circuit operation alternately at every half cycle of a frequency of power from the commercial power source, characterized in that all switching elements are operated substantially at an equal switching frequency while respective switching elements in each series circuit are alternately turned ON and OFF, a timing of turning ON of the switching element in one of the two series circuits and connected to a low potential side of a DC source is substantially equalized to a timing of turning ON of the switching element connected to a high potential side of the smoothing capacitor, and an ON duty ratio of at least one of the switching elements substantially equalized in the turning ON timing is reduced to lower an output to a load.
Dependencies are inferred from the claim text.