Abstract: An electronic system employs multiple power supplies that provide electrical energy to components of the server system. Each power supply exhibits or experiences a uniquely different air flow within the system chassis. Different air flows correspond to different component temperatures for each power supply. Each power supply stores a collection of selectable thermal profiles that determine cooling element control within the power supply. Each thermal profile may correspond to a different physical location within the system. Thermal profiles provide each power supply with local environmental response correlations, such as between local power supply temperature and cooling fan speed. The power supply selects a particular thermal profile in response to determining the power supply's physical location in the system. The power supply instructs the cooling fan to provide an amount of cooling dependent on both the selected thermal profile and a sensed local environmental condition such as temperature.

Abstract: An electronic system employs multiple power supplies that provide electrical energy to components of the server system. Each power supply exhibits or experiences a uniquely different air flow within the system chassis. Different air flows correspond to different component temperatures for each power supply. Each power supply stores a collection of selectable thermal profiles that determine cooling element control within the power supply. Each thermal profile may correspond to a different physical location within the system. Thermal profiles provide each power supply with local environmental response correlations, such as between local power supply temperature and cooling fan speed. The power supply selects a particular thermal profile in response to determining the power supply's physical location in the system. The power supply instructs the cooling fan to provide an amount of cooling dependent on both the selected thermal profile and a sensed local environmental condition such as temperature.

Abstract: The Power Conversion Unit includes a single stage rectifier circuit that generates a DC voltage which is stored on a first capacitor. A circuit arrangement connected to the first capacitor monitors the DC voltage at the capacitor and other predefined signals to generate signals for smoothing ripples associated with the DC voltage and maintains the DC voltage at a predefined level for a predefined time interval. The holdup and smoothing voltages are generated by developing and storing a high voltage on a second capacitor. A switching device connected to the second capacitor causes energy to flow from the second capacitor into the primary winding of a transformer whose secondary winding are switched to deposit the energy stored in said transformer onto the first capacitor. A circuit for charging the second capacitor is also provided.

Abstract: An electronic system employs multiple power supplies that provide electrical energy to components of the server system. Each power supply exhibits or experiences a uniquely different air flow within the system chassis. Different air flows correspond to different component temperatures for each power supply. Each power supply stores a collection of selectable thermal profiles that determine cooling element control within the power supply. Each thermal profile may correspond to a different physical location within the system. Thermal profiles provide each power supply with local environmental response correlations, such as between local power supply temperature and cooling fan speed. The power supply selects a particular thermal profile in response to determining the power supply's physical location in the system. The power supply instructs the cooling fan to provide an amount of cooling dependent on both the selected thermal profile and a sensed local environmental condition such as temperature.

Abstract: The Power Conversion Unit includes a single stage rectifier circuit that generates a DC voltage which is stored on a first capacitor. A circuit arrangement connected to the first capacitor monitors the DC voltage at the capacitor and other predefined signals to generate signals for smoothing ripples associated with the DC voltage and maintains the DC voltage at a predefined level for a predefined time interval. The holdup and smoothing voltages are generated by developing and storing a high voltage on a second capacitor. A switching device connected to the second capacitor causes energy to flow from the second capacitor into the primary winding of a transformer whose secondary winding are switched to deposit the energy stored in said transformer onto the first capacitor. A circuit for charging the second capacitor is also provided.

Abstract: Aspects of a fail safe circuit for protecting power supply operation from a failure are described. The fail safe circuit shutdowns at least one power supply when a preset threshold is exceeded and resets to resume normal operation following a temporary fault condition. The fail safe circuit includes a switch coupled to a voltage signal line of a branch of a power supply system, a current sense resistor coupled to the switch for detecting a failure condition in the branch, and a latch coupled to the current sense resistor and the switch for turning the switch off during the failure condition.

Abstract: Aspects of failure detection of an isolation device in a power supply of a redundant power supply system are described. The aspects include an isolation device coupled to a voltage input line of a power supply. A comparator coupled to the isolation device provides a predictive failure analysis (PFA) signal when the isolation device fails.

Abstract: Aspects for detecting current flow in a power line cord are described. In these aspects, a line current detector circuit is provided for each input plug line of a power distribution box. A determination of whether line current is flowing in a system line cord plugged into the power distribution box is based on a light indicator from the line detector circuit. The line current detector circuit includes a magnetic device for detecting line current flowing in a power line cord, and a light emitting diode (LED) coupled to the magnetic device for outputting a light indicative of whether current is flowing in the power line cord.

Abstract: The present invention provides a highly efficient power supply with redundant multiple input voltage sources. The power supply uses switching transistors, specifically MOSFET's, to create paths for current from one of the voltage sources to the load. The switching transistors are switched either “on” or “off” by comparators which compare the output from the voltage sources. These comparators allow the highest voltage source to provide power to the load, and keep the other switching transistors “off” that connect the common load to other voltage sources. Because the switching transistors have lower conduction losses than diodes in conventional power supplies, the power supply in accordance with the present invention is more efficient.

Abstract: A multiphase zero-volt switching, zero volt switch resonant DC-DC regulator includes: a zero-volt switch zero volt switch; a DC output voltage means; a variable resonant circuit; a synchronous rectifier; and a sensing circuit. The sensing circuit senses a DC output voltage at the DC output of the regulator. The regulator uses the resonant circuit in conjunction with the sensing circuit to provide a substantially constant DC output voltage at a fixed frequency. If the sensing circuit senses a change in the DC output voltage, then a resonant frequency of the regulator is changed by the variable resonant circuit. This allows the oscillator of the regulator to maintain a fixed frequency, thus ensuring the availability of zero-volt switching over the full range of operation. The regulator also has the advantages of low power loss, reduced ripple, and a very fast transient response time.

Abstract: Aspects for detecting current flow in a power line cord are described. In these aspects, a line current detector circuit is provided for each input plug line of a power distribution box. A determination of whether line current is flowing in a system line cord plugged into the power distribution box is based on a light indicator from the line detector circuit. The line current detector circuit includes a magnetic device for detecting line current flowing in a power line cord, and a light emitting diode (LED) coupled to the magnetic device for outputting a light indicative of whether current is flowing in the power line cord.

Abstract: The present invention provides an adapter circuit which improves efficiency and size. The adapter circuit includes: a selective voltage doubler which approximately doubles an input voltage with a low line connector and does not with a high line connector; a switcher coupled to the selective voltage doubler; a resonant circuit coupled to the switcher; a first diode and a second diode coupled to the resonant circuit; and a filter coupled to the first and second diodes. When a low line connector is used, the input voltage is doubled and a one diode drop is used. When a high line connector is used, the input voltage is not doubled and a two diode drop is used. This allows the adapter circuit to be significantly reduced in size and weight. It also has low power loss.

Abstract: An adapter circuit in power supplies utilizes a selective voltage doubler which approximately doubles an input voltage with a low line connector and does not with a high line connector. The selective voltage doubler is coupled to a switcher, which in turn is coupled to a resonant circuit. The resonant circuit is coupled to a first diode and a second diode and a filter. When a low line connector is used, the input voltage is doubled and a one diode drop is used. When a high line connector is used, the input voltage is not doubled and a two diode drop is used.

Abstract: A circuit for limiting inrush current to a power source is disclosed. The circuit includes a low voltage drop semiconductor device coupled to the power source and a resistor coupled in parallel with the low voltage drop semiconductor device. The circuit further includes a diode coupled in parallel with the resistor and an AC detector coupled to the low drop semiconductor device. The AC detector controls the low voltage drop semiconductor device in a manner such that when power is applied to the power source the inrush current to the power source is minimized. The low voltage drop semiconductor device is utilized in conjunction with an AC detector to simultaneously reduce transistor power dissipation and reduce the detrimental effects of inrush current. By reducing the transistor power dissipation as well as the detrimental effects of inrush current, a significant improvement in the overall efficiency of the circuit is achieved.

Abstract: A zero voltage switching synchronous rectification circuit for providing multiple output voltages from a single input voltage is disclosed. The circuit comprises a single transformer coupled to the single input voltage and at least two synchronous rectifiers, each of the at least two synchronous rectifiers being coupled to the transformer via a winding, each of the at least two synchronous rectifiers including a first controlled switching device coupled to the winding, wherein at least one of the at least two synchronous rectifiers includes a delay element, the delay element being coupled to the winding via the first controlled switching device, wherein the delay element delays the input voltage across the at least one of the at least two synchronous rectifiers for a predetermined amount of time. By incorporating a delay element with a plurality of isolated synchronous rectifiers, Zero Voltage Switching is achieved in a multiple output environment.

Abstract: A zero voltage switching synchronous rectification circuit for providing multiple output voltages from a single input voltage is disclosed. The circuit comprises a single transformer coupled to the single input voltage and at least two synchronous rectifiers, each of the at least two synchronous rectifiers being coupled to the transformer via a winding, each of the at least two synchronous rectifiers including a first controlled switching device coupled to the winding, wherein at least one of the at least two synchronous rectifiers includes a delay element, the delay element being coupled to the winding via the first controlled switching device, wherein the delay element delays the input voltage across the at least one of the at least two synchronous rectifiers for a predetermined amount of time. By incorporating a delay element with a plurality of isolated synchronous rectifiers, Zero Voltage Switching is achieved in a multiple output environment.

Abstract: An inductor or transformer uses a multilayer printed circuit board to form the conductor turns. Each layer comprises a dielectric sheet and a conductor printed on the sheet. Each of the conductors has approximately the same shape as each other (such as circular or rectangular), is superimposed on the other conductors and is substantially closed on itself (with a gap to separate the two ends). A multiplicity of through-hole vias are evenly spaced around the conductors and pass through the multiplicity of layers. Successive vias make an electrical connection between successive pairs of adjacent conductors such that current passes in the same direction through all of the conductors. Each layer provides (N-1)/N turns such that N layers provide N-1 complete turns. A ferrite core material passes through a hole in the printed circuit board within the conductors.

Abstract: A three phase input, boost power supply comprises first, second and third rectifiers for respective phases of the three phase input. First, second and third boost inductors are interposed between the first, second and third rectifiers, respectively and respective phases of said three phase input. A low pass filter is interposed between the boost inductors and the three phase input. A chopping switch is connected to an output of at least one of the rectifiers in parallel with a load to boost a voltage of the load. A current sensor is connected between the rectifier output and the load. The switch is activated in response to the current sensor sensing approximately zero current flow. The subsequent rate of current rise is proportional to the magnitude of the input voltage. The switch is deactivated based in part on a comparison of the load voltage to a reference voltage. Thus, the input current for each phase has nearly unity power factor, even when one phase drops out.

Abstract: A power converter comprises a first printed circuit board containing some of the circuitry of the power converter, a header comprising a support structure and a multiplicity of metallic pins passing through the support structure, and an inductor mounted to the support structure and including wires connected to respective pins. Portions of the pins on one side of the support structure are mounted to the first printed circuit board to support the header in fixed offset relation to the first printed circuit board. Portions of the pins on an opposite other side of the support structure are adapted to mount to a second, mother board to support the header in fixed offset relation to the mother board.