3140results about How to "Improve power factor" patented technology

A lamp assembly configured to inductively receive power from a primary coil. The inductively powered lamp assembly includes a lamp circuit including a secondary and a lamp connected in series. In a first aspect, the lamp circuit includes a capacitor connected in series with the lamp and the secondary to tune the circuit to resonance. The capacitor is preferably selected to have a reactance that is substantially equal to or slightly less than the reactance of the secondary and the impedance of the lamp. In a second aspect, the inductively powered lamp assembly includes a sealed transparent sleeve that entirely encloses the lamp circuit so that the transparent sleeve is fully closed and unpenetrated. The transparent sleeve is preferably the lamp sleeve itself, with the secondary, capacitor and any desired starter mechanism disposed within its interior.

A single phase power supply module for electric arc welders and plasma arc cutters comprising: a single phase input stage; positive and negative output terminals; a full wave rectifier connected to the input stage for rectifying the single phase voltage at the input stage; a buck converter type power factor correcting circuit for controlling current flow from the input stage to the rectifier, which buck converter has an output capacitor regulated to an intermediate voltage in the range of 100-150 volts; and, a high speed DC to DC converter having an internal transformer coupling applying voltage across the output terminals and means for regulating the applied voltage to an output voltage in the range of 0-113 volts. The module is universal and several can be connected in parallel, in series or to switch networks to construct several welders or cutters.

A dimmable light-emitting diode (LED) lamp and a dimmable LED lighting apparatus thereof are provided. The dimmable LED lamp includes a bridge rectifier, a toggle detector, a sustain voltage supply circuit, a counter, an LED light source, and an LED lighting driver. The bridge rectifier receives a source alternating current (AC) voltage through a wall switch and provides a rectified direct current (DC) voltage. The toggle detector monitors a toggle action of the wall switch. The sustain voltage supply circuit provides a sustain voltage. The counter receives the sustain voltage for operation. Moreover, the counter stores and provides an counting value that changes when the toggle detector detects the toggle action. The LED lighting driver converts the rectified DC voltage to a constant current to drive the LED light source. The LED lighting driver also provides multi-level dimming to the LED light source according to the counting value.

A dimmable light-emitting diode (LED) lamp and a dimmable LED lighting apparatus thereof are provided. The dimmable LED lamp includes a bridge rectifier, a toggle detector, a sustain voltage supply circuit, a counter, an LED light source, and an LED lighting driver. The bridge rectifier receives a source alternating current (AC) voltage through a wall switch and provides a rectified direct current (DC) voltage. The toggle detector monitors a toggle action of the wall switch. The sustain voltage supply circuit provides a sustain voltage. The counter receives the sustain voltage for operation. Moreover, the counter stores and provides an counting value that changes when the toggle detector detects the toggle action. The LED lighting driver converts the rectified DC voltage to a constant current to drive the LED light source. The LED lighting driver also provides multi-level dimming to the LED light source according to the counting value.

A power factor correcting power supply includes an input stage power converter and an output stage power converter. The input stage power converter includes a plurality of series connected boost switches and a power factor correction controller. The power factor correction controller may direct the operation of the boost switches with series interleave phasing to perform power factor correction and voltage regulation. The boost switches are supplied input voltage and input current from a power source. The input voltage is converted to a DC boost voltage by high frequency series interleaved switching of the boost switches. The DC boost voltage is converted to a DC output voltage by the output stage power converter. The DC output voltage is provided on a DC rail for a load of the power factor correcting power supply.

A power factor correcting power supply includes an input stage power converter and an output stage power converter. The input stage power converter includes an opposed current converter and a power factor correction controller. The power factor correction controller may direct the operation of the opposed current converter to perform power factor correction and voltage regulation. The opposed current converter is supplied AC input voltage and AC input current from a power source. The AC input voltage is converted to a DC boost voltage by the opposed current converter. The DC boost voltage may be converted to a desired DC output voltage by the output stage power converter. The desired DC output voltage may be provided on a DC rail for a load of the power factor correcting power supply.

A vehicle motor-generator apparatus based on a field winding type of synchronous machine coupled to a power inverter and a battery, wherein the synchronous machine is controlled to operate as a motor to perform engine starting and thereafter be driven by the engine as an electrical generator, wherein during a short time interval at the commencement of engine starting, the armature winding of the synchronous machine is driven by a current such that magnetic flux is produced by the armature winding acting in the same direction as magnetic flux produced by the field winding, to thereby achieve increased torque during the time when maximum torque is required. In addition, the supplied field current is set at a maximum value during only an initial period when engine starting begins, until the first compression stroke of the engine has been completed, and thereafter set to a reduced value until the completion of engine starting, thereby reducing the amount temperature rise within the field winding during engine starting, while ensuring a sufficiently high value of initial torque.

The invention provides a self-oscillation type high power LED constant-current drive circuit with low cost, high reliability and stability and high drive efficiency, the circuit comprises a rectifier and filter circuit, a switching circuit, a steady voltage constant current output circuit, a transformer, a self-oscillation type pulse width modulation signals generating circuit and a current feedback obstruction circuit, wherein the rectifier and filter circuit accesses commercial power into rectification, changes the commercial power into direct current, and then outputs commercial power to the switching circuit to switch in a self-oscillation type with high frequency, then high frequency voltage of the steady voltage constant current output circuit is transformed into direct voltage through the transformer to drive the LED, simultaneously sampling current signals produces jam signals through the current feedback obstruction circuit to control the switching circuit to work, the circuit does not adopt any driving chips and only uses fewer common individual devices to form a self-oscillation type structure to drive the switching circuit and to combine current feedbacks, which realizes constant current driving of the high power LED.

The invention relates to the field of dimming and speed regulation related to illumination, motors and electronics, in particular to a motor-driven circuit for dimming or speed regulation control which is suitable for illumination of a silicon-controlled dimmer or adjustment of a silicon-controlled speed regulator and a control method. A detection compensation circuit for maintaining the normal work of the silicon-controlled dimmer consists of a voltage detection circuit, a current detection circuit, a follow current compensation circuit and a power factor compensation circuit; the on-off running state of the silicon-controlled dimmer or speed regulator is detected by a detection method combining output voltage change and current change of the silicon-controlled dimmer or speed regulator;the on-off and trigger running conditions of the silicon-controlled dimmer are provided by adopting a compensation method combining power factor compensation and follow current compensation; a control circuit of a load consists of a datum transformation circuit, an output duty cycle control circuit, an output current control circuit and a drive output circuit and produces a control signal by detecting mains supply AC phase-shedding operation output of the silicon-controlled dimmer or speed regulator; and the output power of the load is controlled by a load output duty cycle and load working current compound control method so as to realize large output power adjustable range of the load and high linearity of the adjusting process.