Power-factor-corrected AC/DC converter

An arrangement comprising:

• rectifier means connected with the power line voltage from an ordinary electric utility power line and operative to provide at a first DC output a first DC voltage having an instantaneous absolute magnitude approximately equal to that of the power line voltage;
• inverter means connected with the first DC output and operative to provide an AC voltage at an AC output, the frequency of the AC voltage being substantially higher than that of the power line voltage, the instantaneous absolute magnitude of the AC voltage being substantially proportional to that of the power line voltage;
• and
• conversion means connected with the AC output and operative to provide a second DC voltage at a second DC output, the magnitude of the second DC voltage being substantially constant, the magnitude of the current drawn by the conversion means from the AC output being substantially independent of the magnitude of the AC voltage;
• whereby the magnitude of the current drawn by the rectifier means from the power line is substantially constant for as long as current is being provided to the conversion means from the AC output.

An arrangement comprising:

• first means conditionally operative to provide a periodically intermittent AC voltage at an AC output, the first means having prevent means operative in response to a control action to prevent the provision of the periodically intermittent AC voltage;
• second means connected with the AC output and operative to provide a DC voltage at a DC output, an energy-storing means being connected in circuit with the DC output;
• and
• third means connected in circuit between the DC output and the control means, the third means being responsive to the magnitude of the DC voltage and operative, whenever the magnitude of the DC voltage exceeds a first predetermined level, to provide said control action.

An arrangement comprising:

• first means operable to connect with the power line voltage on an ordinary electric utility power line and operative, when so connected, to provide a first DC voltage at a first DC output, the output impedance of the first DC output being relatively low, the instantaneous absolute magnitude of the first DC voltage being about the same as that of the power line voltage;
• second means connected with the DC output and operative to provide an AC voltage at an AC output, the output impedance of the AC output being relatively low, the AC voltage being:
• i) of instantaneous absolute magnitude substantially proportional to that of the first DC voltage, and ii) of frequency substantially higher than that of the power line voltage;
• third means connected with the AC output and operative to provide a unidirectional current at a second DC output, the output impedance of the second DC output being relatively high;
• and
• energy-storing capacitor means connected with the second DC output and operative to receive the unidirectional current provided therefrom, thereby to develop a second DC voltage of a DC terminal means, the magnitude of the second DC voltage being substantially constant for the duration of a complete cycle of the power line voltage, the DC terminal means being operative to connect with a DC load means.

The arrangement comprising:

• a source of DC voltage;
• inverter means connected with the source of DC voltage and conditionally operative to provide a squarewave voltage at an inverter output, the inverter means having control input means operative in response to a control input to remove the squarewave voltage from the inverter output, the squarewave voltage having a fundamental frequency;
• a series-combination of an inductor and a capacitor connected across the inverter output, the series-combination being resonant at or near the funamental frequency;
• rectification means connected in parallel circuit with the capacitor and operative to supply a unidirectional current at a pair of DC current terminals;
• and
• filter means connected with the DC current terminals and operative to provide a filtered DC voltage at a pair of DC voltage terminals.