Power control apparatus and electronic appliance equipped with power control apparatus
A power control apparatus includes an input terminal and an output terminal for an AC signal; a DC removing capacitor connected between the input terminal and the output terminal; and a variable capacitor that is connected between the input terminal and the output terminal and whose capacitance can be changed by a control signal. One of a current and a voltage of the AC signal is controlled by changing the capacitance of the variable capacitor using the control signal, and dielectrics that form a serially connected row of capacitors composed of the DC removing capacitor and the variable capacitor are configured so as to be integrally laminated, and the control signal is applied across a dielectric that forms the variable capacitor and the AC signal is applied across the dielectrics that form the row of capacitors.
1. A power control apparatus comprising:
an input terminal and an output terminal to connect to an AC source;
a DC removing capacitor connected between the input terminal and a control terminal to remove DC currents flowing between the input terminal and the output terminal; and
a variable capacitor connected between the control terminal and the output terminal, a capacitance of the variable capacitor varying according to a control signal continuously applied between the control terminal and the output terminal, one of a current and a voltage of an AC signal supplied by the AC source being controlled by changing the capacitance of the variable capacitor using the control signal,
wherein dielectrics that form the DC removing capacitor and the variable capacitor as a serially connected row of capacitors are integrally laminated, and the DC removing capacitor and the variable capacitor are connected in series between the input terminal and the output terminal, and
wherein a thickness between the dielectrics that form the row of capacitors and a distance between electrodes of the dielectrics are changed to change a combined capacitance, a withstand voltage, and a variable range of the combined capacitance of the DC removing capacitor and the variable capacitor.
2. A power control apparatus according to claim 1 , wherein the combined capacitance, the withstand voltage, and the variable range of the combined capacitance of the DC removing capacitor and the variable capacitor are changed by respectively connecting at least one other DC removing capacitor and at least one other variable capacitor to the DC removing capacitor and the variable capacitor in parallel.
3. A power control apparatus according to claim 2 , wherein the row of capacitors has a two-element construction including the DC removing capacitor and the variable capacitor connected in series,
a capacitance of the DC removing capacitor proportionally increases with relative to the at least one other DC removing capacitor connected in parallel, and
a capacitance of the variable capacitor is proportionally increased by the at least one other variable capacitor connected in parallel.
4. A power control apparatus according to claim 2 , wherein the row of capacitors has a three-element construction where a plus-side DC removing capacitor, the variable capacitor, and a minus-side DC removing capacitor are connected in series, and a capacitance of the variable capacitor is proportionally increased by connecting other variable capacitors in parallel thereto.
5. A power control apparatus according to claim 2 , wherein the row of capacitors has a three-element construction where a plus-side DC removing capacitor, the variable capacitor, and a minus-side DC removing capacitor are connected in series,
a capacitance of the plus-side DC removing capacitor is proportionally increased by connecting other DC removing capacitors in parallel thereto, and
a capacitance of the minus-side DC removing capacitor is proportionally increased to by connecting other DC removing capacitors in parallel thereto.
6. A power control apparatus according to claim 2 , wherein the row of capacitors has a four-element bridge construction where the variable capacitors are connected in series, capacitances of four elements are adjusted such that capacitances of two pairs of balancing elements out of the four elements are equal, and two out of the four elements are used as the DC removing capacitor, capacitances thereof are fixed, and capacitances of another two out of the four elements are variable.