Abstract: A control device controls non-excitation-actuated electromagnetic brake operation. The control device includes an electronic component having a characteristic that when an inter-terminal voltage of two electrodes is equal to or higher than a predetermined voltage, a resistance value is lower than when the voltage is lower than the voltage and a diode disposed such that a cathode is on a side having a higher potential than an anode. The coil in the non-excitation-actuated electromagnetic brake and the electronic component are connected in series to form a first series circuit, the first series circuit and the diode are connected in parallel, and the electronic component is connected in series with the coil provided in the non-excitation-actuated electromagnetic brake so as not to be conducted when the inter-terminal voltage is lower than the predetermined voltage, but to be conducted when the inter-terminal voltage becomes equal to or higher than the predetermined voltage.

Abstract: A control device controls non-excitation-actuated electromagnetic brake operation. The control device includes an electronic component having a characteristic that when an inter-terminal voltage of two electrodes is equal to or higher than a predetermined voltage, a resistance value is lower than when the voltage is lower than the voltage and a diode disposed such that a cathode is on a side having a higher potential than an anode. The coil in the non-excitation-actuated electromagnetic brake and the electronic component are connected in series to form a first series circuit, the first series circuit and the diode are connected in parallel, and the electronic component is connected in series with the coil provided in the non-excitation-actuated electromagnetic brake so as not to be conducted when the inter-terminal voltage is lower than the predetermined voltage, but to be conducted when the inter-terminal voltage becomes equal to or higher than the predetermined voltage.

Abstract: An indoor-unit transmission/reception unit and an outdoor-unit transmission/reception unit are connected via a first signal line, and another indoor-unit transmission/reception unit and another outdoor-unit transmission/reception unit are connected via a second signal line. A first return switch is connected between a first power supply line and the first signal line, and a second return switch is connected between the first power supply line and the second signal line. A first end of a second switch is connected to the first power supply line, and a second end of the second switch is connected to the cathodes of two diodes. The anodes of the first and the second diodes are connected to the first and the second signal lines, respectively. A common end of the second switch is connected to the first end or the second end thereof. An outdoor-power supply unit is fed with electric power from the common end of the second switch and the second power supply line.

Abstract: A first conversion section converts, into a first direct-current voltage, an alternating-current voltage input from input lines, and applies the same between power supply lines. A diode is arranged between the power supply lines such that an anode thereof faces toward the power supply line side. A capacitor has both ends connected to a direct-current load, and is connected in series with the diode. A switch section selects conduction/non-conduction between an alternating-current power supply and the first conversion section. A second conversion section converts, into a second direct-current voltage, the alternating-current voltage input without passing through the switch section, and is connected to a connection point located between the capacitor and the diode to apply the second direct-current voltage to the capacitor.

Abstract: A first conversion section converts, into a first direct-current voltage, an alternating-current voltage input from input lines, and applies the same between power supply lines. A diode is arranged between the power supply lines such that an anode thereof faces toward the power supply line side. A capacitor has both ends connected to a direct-current load, and is connected in series with the diode. A switch section selects conduction/non-conduction between an alternating-current power supply and the first conversion section. A second conversion section converts, into a second direct-current voltage, the alternating-current voltage input without passing through the switch section, and is connected to a connection point located between the capacitor and the diode to apply the second direct-current voltage to the capacitor.