Abstract: A power converter with an enhanced power conversion factor interfaces with electrical utility alternating current (AC) power sources to drive low voltage electrical loads. A high frequency drive signal is provided by an oscillating power driver stage. Enhanced power conversion efficiencies are achieved using an uninterrupted wave operation of the high frequency oscillating power driver stage used to effect power conversion. Components of the power converter are protected by suppressing the oscillation of the oscillating power driver stage for as long as electrical fault conditions persist. The advantages include power savings, an extended life of power converter components, reduced heat output and reduced stress on power converter components during electrical faults.

Abstract: A power supply circuit employed in various types of electronic appliances, telecommunications equipment, and the like, is provided for generating a voltage pulse by resonance effect of a primary side of a transformer, and outputting the voltage pulse from a secondary side after raising a voltage thereof. The power supply suppresses fluctuations of electric current, and prevents noise from being propagated through a device powered by the supply. A control circuit actuates a second switching element into a non-conducting state while a first switching element is in a conducting state. The power supply switches the second switching element into a conducting state when voltage of a primary coil is greater than voltage of a driving power supply after an electric current flows in a first diode while the first switching element is in a non-conducting state.

Abstract: A DC-DC power converter, and, more specifically, an active snubber circuit, method of operation thereof and power converter employing the same, and more specifically, a pulse width modulated DC-DC power converter which processes power from an input DC voltage source and delivers power to a load through an inductive energy storage component being alternatively connected to the input DC power source and to the load via electronic solid state switches.

Abstract: A switching circuit, a method of processing power and a single stage power factor corrector employing the switching circuit or the method. In one embodiment, the switching circuit includes: (1) a power switch coupled to a primary winding of a transformer; and (2) an active clamp coupled to the power switch. The active clamp includes: (2a) series-coupled first and second capacitors, coupled across the power switch and the primary winding, having opposing polarities thereacross, and (2b) a clamping switch coupled to a node between the series-coupled first and second capacitors. The clamping switch opens to allow energy stored in the first capacitor to be transferred to an output of the power converter via the second capacitor. The clamping switch further closes to allow energy stored in the second capacitor to be transferred to the output.

Abstract: A power supply controller having a multi-function terminal. In one embodiment, a power supply controller for switched mode power supply includes a drain terminal, a source terminal, a control terminal and a multi-function terminal. The multi-function terminal may be configured in a plurality of ways providing any one or some of a plurality of functions including on/off control, external current limit adjustments, under-voltage detection, over-voltage detection and maximum duty cycle adjustment. The operation of the multi-function terminal varies depending on whether a positive or negative current flows through the multi-function terminal. A short-circuit to ground from the multi-function terminal enables the power supply controller. A short-circuit to a supply voltage from the multi-function terminal disables the power supply controller. The current limit of an internal power switch of the power supply controller may be adjusted by externally setting a negative current from the multi-function terminal.

Abstract: A compact, economical and fast battery charger for Ni-CAD and Ni-MH batteries turns a current source into a controlled voltage source which keys off a signal representative of the voltage level of the battery during the charging process and turns the current source ON and OFF to assure that the battery during the charging process does not exceed a given voltage level. The apparatus includes in par a ballasting resistor in series with the battery to compensate for the low resistance of the battery and an open collector voltage comparator which establishes high and low voltage set points for turning the current source ON and OFF at the appropriate times. The method and apparatus includes a visual display responsive to a signal which produces on the visual display an indication of the state of charge of the battery during a charging cycle. A circuit board has a long U-shaped trace extending around a notch in the board, on each side of each is mounted on battery.

Abstract: The invention relates to a DC voltage converter comprising first and second input terminals for receiving an input voltage, a choke component having a first terminal coupled to the first input terminal and a second terminal coupled to a first terminal of a capacitive branch which has a second terminal coupled to the second input terminal, first and second switches controlled in opposition, and an output transformer having a primary and a secondary feeding a load. The capacitive branch presents two capacitive components connected in series with the common terminal thereof being coupled to a first terminal of the primary of said output transformer. The first and second switches are connected in series and present a common terminal coupled to a second terminal of the primary of said output transformer, the other terminals of the first and second switches being coupled respectively to the first and second terminals of the capacitive branch.

Abstract: An integrated circuit has a MOSFET comprising a drain terminal, a source terminal and a gate control terminal, the MOSFET having an equivalent circuit that includes an intrinsic diode; and a diode comprising an anode terminal and a cathode terminal.

Abstract: A d.c.-to-d.c. converter of the kind having a step-up or step-down transformer with a primary to be connected to a d.c. power supply via an electronic switch, and a secondary to be connected to a load via a smoothing and rectifying circuit. The voltage being applied to the load is detected and fed back to a switch control circuit whereby the switch is controlled to keep constant the converter output voltage. Connected in parallel with the transformer primary, a surge suppressor circuit has a serial connection of a surge-absorbing capacitor and a rectifying diode and a resistor for absorbing a surge developing across the transformer primary winding each time the switch is turned off.

Abstract: A switching power supply circuit includes a transformer having a primary winding, a secondary winding, and a feedback winding, a switching element connected in series to a first of the primary winding, a control circuit disposed between a control terminal of the switching element and the feedback winding, a starting circuit connected between a second end of the primary winding and the control terminal of the switching element, and a rectifying/smoothing circuit connected to the secondary winding.