Abstract: According to one embodiment, a circuit for providing redundant power includes a first channel having a first input, a first electronic circuit breaker, and a first output, a second channel having a second input, a second electronic circuit breaker, and a second output, and a first transistor coupled to the first electronic circuit breaker, the first transistor in series with a second transistor coupled to the second channel. The circuit normally operates by providing power to the first and second outputs from the first and second channels, respectively. However, if the first channel fails, the transistors switch on to allow power from the second channel to feed the first output in the first channel in addition to feeding power to the second output, and vice versa. Other embodiments and methods for providing redundant power are described as well.

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: An alternating current-to-direct current (AC-to-DC) power supply has a first stage providing a first DC voltage and a second stage providing a second DC voltage. The AC-to-DC power supply has a first efficiency at the first stage and a second efficiency at the second stage that is less than the first efficiency. The second DC voltage is also less than the first DC voltage. A blower is electrically connected to the first stage of the AC-to-DC power supply to receive the first DC voltage from the AC-to-DC power supply to power the blower. Electrical connection of the blower to the first stage of the AC-to-DC power supply instead of to the second stage of the AC-to-DC power supply wastes less power and is more efficient.

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 apparatus, system, and method are disclosed for determining power source failure. A sampling module samples an alternating current power waveform as input to a power supply, at a sampling frequency which is a multiple of a predetermined frequency, to obtain a sampled amplitude at a known point within the predetermined period. A comparison module compares the sampled amplitude to a stored threshold amplitude to obtain a comparison result, corresponding to the known point. An accumulation module accumulates most recent comparison results. A warning module asserts an early power off warning signal if a predetermined number of the most recent comparison results each indicate that the sampled amplitude is smaller in absolute value than the stored threshold amplitude.

Abstract: A positive temperature coefficient device is configured in parallel with a bypass switch and implemented at an input to a switching regulation stage of a switching power supply. A monitoring module determines that a voltage across the regulation switch in the switching power supply is below a predefined threshold voltage for greater than a predefined threshold time period. A control module controls operation of the bypass switch. The control module opens the bypass switch in response to the monitoring module determining that the voltage across the regulation switch is below the predefined threshold voltage for greater than the predefined threshold time period such that substantially all of the current entering the switching regulation stage passes through the PTC device. By causing substantially all of the current to pass through the PTC device, the device will enter a high impedance state thereby preventing smoke and smell from occurring.

Abstract: An apparatus, system, and method are disclosed for providing regulated electric power. At least two power buses transfer regulated direct current (“DC”) power from at least four power supplies to an electric load. The power supplies receive electric power from one or more electric sources and convert the electric power to the regulated DC electric power. A switch is connected between each of the power buses and the electric load. Each switch connects and disconnects a power bus to the electric load and transfers the regulated DC electric power from the buses to the electric load. An output power bus connection is disposed on each of the power supplies. Each of the power buses is connected to at least two power supplies and each output power bus connection connects the corresponding power supply upon which the output power bus connection is disposed to exactly one power bus.

Abstract: An apparatus, system, and method are disclosed for efficiently providing bias voltages. A first switching regulator stage that includes an inductor receives an input voltage and provides as an output an intermediate regulated output voltage. A second switching regulator stage receives as input the intermediate regulated output voltage and outputs a regulated main output voltage. The second switching regulator stage includes at least one switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage. A secondary bias module utilizes a secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the switch controller of the second switching regulator stage. The secondary bias output voltage is referenced to the main output voltage of the second switching regulator stage.

Abstract: An apparatus, system, and method are disclosed for controlling fan speed in a power supply. The apparatus measures input power to the power supply and measures the output power provided by the power supply over an interval. The apparatus determines values for the input power and output power and, using the two, determines how much power has been dissipated in the power supply. Power dissipation values are associated with particular fan speeds, and the apparatus adjusts the speed of the fan in the power supply based on how much power was dissipated during the interval. Increasing levels of power dissipation increases the fan speed, and decreasing levels of power dissipation decrease the fan speed.

Abstract: According to one embodiment, a circuit for providing redundant power includes a first channel having a first input, a first electronic circuit breaker, and a first output, a second channel having a second input, a second electronic circuit breaker, and a second output, and a first transistor coupled to the first electronic circuit breaker, the first transistor in series with a second transistor coupled to the second channel. The circuit normally operates by providing power to the first and second outputs from the first and second channels, respectively. However, if the first channel fails, the transistors switch on to allow power from the second channel to feed the first output in the first channel in addition to feeding power to the second output, and vice versa. Other embodiments and methods for providing redundant power are described as well.

Abstract: An alternating current-to-direct current (AC-to-DC) power supply has a first stage providing a first DC voltage and a second stage providing a second DC voltage. The AC-to-DC power supply has a first efficiency at the first stage and a second efficiency at the second stage that is less than the first efficiency. The second DC voltage is also less than the first DC voltage. A blower is electrically connected to the first stage of the AC-to-DC power supply to receive the first DC voltage from the AC-to-DC power supply to power the blower. Electrical connection of the blower to the first stage of the AC-to-DC power supply instead of to the second stage of the AC-to-DC power supply wastes less power and is more efficient.

Abstract: An apparatus for error checking in a power supply includes a power module that determines that the power supply is in a self-test condition. The self-test condition involves the power supply being connected to an input power source while it is disconnected from the electronic load that it normally services. A load module connects an internal test load to the power supply when the power supply is in self-test condition, and an error checking module performs error check operations on the power supply while it is connected to the test load. The apparatus also includes a notify module that actuates an indicator when the error checking module determines that there are one or more faults in the power supply. The apparatus may also include a log module for storing error messages and reports in non-volatile memory.

Abstract: An apparatus, system, and method are disclosed for safely connecting a device to a power source. The invention includes a power bus switch that operates to selectively allow operational power to flow from a power supply to a load. The operational power is independent of auxiliary power which may be separately provided to the load. A detection module determines whether an input impedance of the load is greater than a minimum impedance threshold in response to the load being connected to the power supply. A switch module causes the power bus switch to allow operational power to flow to the load in response to the detection module determining that the input impedance is greater than the minimum impedance threshold. Thus, if the load has an acceptable input impedance level, then operational power may be provided to the load without risk of failure to the power system.

Abstract: A positive temperature coefficient device is configured in parallel with a bypass switch and implemented at an input to a switching regulation stage of a switching power supply. A monitoring module determines that a voltage across the regulation switch in the switching power supply is below a predefined threshold voltage for greater than a predefined threshold time period. A control module controls operation of the bypass switch. The control module opens the bypass switch in response to the monitoring module determining that the voltage across the regulation switch is below the predefined threshold voltage for greater than the predefined threshold time period such that substantially all of the current entering the switching regulation stage passes through the PTC device. By causing substantially all of the current to pass through the PTC device, the device will enter a high impedance state thereby preventing smoke and smell from occurring.

Abstract: An apparatus, system, and method are disclosed for controlling fan speed in a power supply. The apparatus measures input power to the power supply and measures the output power provided by the power supply over an interval. The apparatus determines values for the input power and output power and, using the two, determines how much power has been dissipated in the power supply. Power dissipation values are associated with particular fan speeds, and the apparatus adjusts the speed of the fan in the power supply based on how much power was dissipated during the interval. Increasing levels of power dissipation increases the fan speed, and decreasing levels of power dissipation decrease the fan speed.

Abstract: An apparatus, system, and method are disclosed for determining power source failure. A sampling module samples an alternating current power waveform as input to a power supply, at a sampling frequency which is a multiple of a predetermined frequency, to obtain a sampled amplitude at a known point within the predetermined period. A comparison module compares the sampled amplitude to a stored threshold amplitude to obtain a comparison result, corresponding to the known point. An accumulation module accumulates most recent comparison results. A warning module asserts an early power off warning signal if a predetermined number of the most recent comparison results each indicate that the sampled amplitude is smaller in absolute value than the stored threshold amplitude.

Abstract: An apparatus, system, and method are disclosed for efficiently providing bias voltages. A first switching regulator stage that includes an inductor receives an input voltage and provides as an output an intermediate regulated output voltage. A second switching regulator stage receives as input the intermediate regulated output voltage and outputs a regulated main output voltage. The second switching regulator stage includes at least one switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage. A secondary bias module utilizes a secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the switch controller of the second switching regulator stage. The secondary bias output voltage is referenced to the main output voltage of the second switching regulator stage.

Abstract: An apparatus, system, and method are disclosed for determining fan rotation direction. A first temperature detection module detects a first temperature at a first location between a fan and a heat generating device. The fan provides cooling for the heat generating device by drawing air from the heat generating device across the first location to the fan when the fan is rotating in a first direction. A second temperature detection module detects a second temperature at a second location where the heat generating device is between the second location and the fan such that heat from the heat generating device is drawn away from the second location when the fan is rotating in the first direction. A temperature comparison module determines if the second temperature is above the first temperature. A fan rotation error module generates a fan rotation error signal if the second temperature is above the first temperature.

Abstract: An apparatus, system, and method are disclosed for safely connecting a device to a power source. The invention includes a power bus switch that operates to selectively allow operational power to flow from a power supply to a load. The operational power is independent of auxiliary power which may be separately provided to the load. A detection module determines whether an input impedance of the load is greater than a minimum impedance threshold in response to the load being connected to the power supply. A switch module causes the power bus switch to allow operational power to flow to the load in response to the detection module determining that the input impedance is greater than the minimum impedance threshold. Thus, if the load has an acceptable input impedance level, then operational power may be provided to the load without risk of failure to the power system.