Abstract: An OLED driver possesses a square-wave voltage source, a controller and a detector. In accordance with first control, the source generates square-wave voltage and applies the voltage across at least one organic electroluminescence element to drive the element. The controller controls the source in accordance with the first control. The detector detects equivalent capacitance inherent in the element. The controller also judges whether or not the element is normal based on the equivalent capacitance. If the element is normal, the controller operates in accordance with the first control. If the element is not normal, the controller operates in accordance with predetermined second control for the element which is not normal.

Abstract: An inverter device has a full-wave rectifier providing a pulsating DC voltage from an input AC voltage, a smoothing circuit. The smoothing circuit includes a choke coil, a smoothing capacitor and a switching element chopping the pulsating DC voltage through the choke coil into a smoothed DC voltage at the smoothing capacitor. An inverter is included to have the element common to the smoothing circuit and operating to switch the smoothed DC voltage to apply a resulting voltage to a load circuit including a load, inductance and capacitor. The inductance and capacitor define an oscillation circuit providing to the load an oscillating current composed of first and second currents of opposite directions. The oscillating current alternating to flow for a nominal on-time duration determined by a circuit constant of the oscillation circuit itself.

Abstract: A power source for providing a high frequency ac output voltage is provided with a rectifier, a smoothing circuit with an inductor and a smoothing capacitor, and an inverter having a switching device for switching the input dc voltage from the rectifier to provide a high frequency ac voltage output with reduced ripple. Also included in the smoothing circuit is a charge storage device by the operation of which the inductor receives electromagnetic energy from the current therein when the switching device is switched on and electromagnetic energy is fed to the smoothing capacitor to charge the same when the switching device is switched off, with the resulting voltage developed across the capacitor being applied to the inverter input.

Abstract: A power supply apparatus is structured such that the output of an alternating current voltage source (1) is connected to the input of a rectifying circuit (2), a series connection of a first smoothing capacitor (3a), a diode (15) and a second smoothing capacitor (3b) is connected to the output of the rectifying circuit so that the rectifying direction of the diodes may be opposite to the rectifying direction of the rectifying circuit, a first load (4a) is connected in parallel with the series connection portion of the first smoothing capacitor and the diode, and a second load (4b) is connected in parallel with the series connection portion of the second smoothing capacitor and the diode.