Abstract: The solid state switching section of a high frequency PWM switching power supply may encounter problems in accurately regulating output power when the requested output power is above a threshold level, the threshold level typically being a high level approaching one hundred percent of the power of the sinusoidal AC power source. Below the threshold level, the power supply is operated in a full PWM mode to regulate the output power level. Above the threshold level, the power supply is operated in a full on, continuously conducting mode in a central part of the half cycles of the AC supply. Outside of this central portion, the power supply is operated in the in the PWM mode, using a duty cycle within the capability of the solid state switching section. The output power level is regulated by varying the duration of the central full on portion of the half cycle. A similar control method is used for reducing heat generated by the solid state switching section of the power supply.

Abstract: A power supply system for liquid crystal monitors includes a first DC/AC converter (FBS, HBS) operating at predetermined frequency and duty-cycles and being fed by a second DC/DC converter (FC) which regulates the circuit voltage. The feeding system can feed all the fluorescent lamps (L, L1, LN) in the monitor through a bus connection which transmits the output sinusoidal voltage (SG1, SG2, SG3) from the first DC/AC converter (FBS, HBS) to the primary windings of a plurality of parallel connected piezoelectric transformers (PT, PT1, PT2, PTN, PT2N) which are connected with the fluorescent lamps (L, L1, LN).

Abstract: An apparatus for driving a lamp of a liquid crystal display device includes a transformer to supply a voltage to a lamp and a voltage detector having a first resistance connected between a secondary winding wire of the transformer and a ground voltage source, a rectifier connected to the secondary winding wire of the transformer, and a second resistance connected between the rectifier and the ground voltage source to detect a voltage induced onto the secondary winding wire of the transformer.

Abstract: Multiple lighting apparatus coupled together to form a lighting network, in which operating power is efficiently provided throughout the network based on a distributed DC voltage or a distributed AC voltage. Based on various power driver configurations, each lighting apparatus incorporates one or more power drivers for one or more LED-based loads. In one example, a controlled predetermined power is provided to a load without requiring any feedback information from the load (i.e., without monitoring a load voltage and/or load current). In another example, a “feed-forward” power driver for an LED-based light sources combines the functionality of a DC-DC converter and a light source controller, and is configured to control the intensity of light generated by the light source based on modulating the average power delivered to the light source in a given time period, without monitoring and/or regulating the voltage or current provided to the light source.

Abstract: A method for stabilizing brightness of a cold cathode fluorescent lamp includes receiving currents from two ends of the cold cathode fluorescent lamp and providing a current for the cold cathode fluorescent lamp according to a lower current of the currents received from the two ends of the cold cathode fluorescent lamp.

Abstract: The present invention is an inverter controller with feed-forward compensation. The inverter controller includes an error amplifier, a high frequency oscillator (HFOSC) with feed-forward compensation, a comparator, and a driver. The error amplifier can output a signal independent on the variation of a supply voltage. The HFOSC can generate a saw-tooth signal with a constant frequency and an amplitude proportional to the supply voltage. The comparator can compare the signal with the saw-tooth signal and generate a pulse width modulation signal whose duty cycle varies with the variation of the supply voltage. The driver receives the PWM signal and provides a proper pulse width modulation signal to drive an external inverter.

Abstract: A line deflection circuit for a television receiver having a deflection coil, an S capacitor for S correction of the linearity of the deflection, the capacitor being connected in series with the deflection coil, and having means for changing over the linearity of the line deflection current for a change of the picture aspect ratio, wherein the means for changing the picture aspect ratio comprise a network formed by an inductance and a capacitance which are connected in series, wherein the network is tuned to approximately the line trace period, wherein a switch is provided to switch the network between an operative and a non-operative state, and wherein the network in its operative state is connected in parallel to the S capacitor.

Abstract: The invention relates to a method and to a circuit arrangement used to regulate synchronous linear motors, especially linear drive mechanisms in film drawing systems. The force (Fclip) between the stationary primary part and the moved secondary part is determined in a sensorless manner from the voltages and currents calculated and measured in a frequency converter in a functional block, in such a manner that the integral is calculated from the active power during a time period (tclip) between two pulses (new—clip) produced by an overriding control and said integral is divided by the active length (1zone) of the primary part. Alternatively, the force (Fclip) can also be determined by summation of the voltages in the f-axis in order to reduce the drop in voltage in relation to the resistance (Rstr) of the branch in the primary part. Voltages and currents are transformed on the primary part by a co-ordinate system related to the secondary part.

Abstract: Detecting the presence of an electric fan is described. A current sink circuit is coupled to a pulse width drive output of a fan control circuit. A logic state in a logic input buffer is defined based on current flow through the current sink. The logic state indicates if a fan is coupled to the pulse width drive output.

Abstract: A fan speed control circuit includes a pulse width modulation (PWM) signal generating circuit, a driving circuit and a phase compensation unit. The PWM signal generating circuit generates a PWM control signal with a sequence of alternating on-time and off-time, and the driving circuit outputs a driving signal according to the PWM control signal to a fan motor. The phase compensation unit is connected to the fan motor for delaying or advancing the PWM control signal by a phase angle to synchronize the acting period of the back electromotive force formed by the magnetic flux variation with the off-time of the PWM control signal. The present invention further provides a bi-power motor driving system including a motor rotating by receiving a first power from a first power generator, and a driving circuit for driving the motor according to a second power from a second power generator.

Abstract: Disclosed is a pressing sensing technology of a self-running robot, comprising a pressing sensing unit for sensing pressing on the top of the self-running robot and a microprocessor for controlling driving of the self-running robot in accordance with the sensing signal from the pressing sensing unit to enable the self-running robot to escape from an area where the pressing has occurred. Accordingly, the invention has an advantage in that it can prevent a function degradation and damage of the self-running robot by changing a running direction of the self-running robot when pressing on the self-running robot is sensed to enable the self-running robot to escape from the area where the pressing has occurred, or notifying, when the pressing cannot be released, a user of the state in voice to take any necessary action.

Abstract: A method of and system for identifying the position of magnetic poles of a rotor of a multi-phase electrical machine relative to a stator of that machine is disclosed. The method includes the steps of applying a voltage pulse to stator windings of each phase, sensing current flow in the stator windings of each phase due to the application of the voltage pulse to the respective stator windings and determining the position of the magnetic poles of the rotor relative to the stator using the sensed current flow in the stator windings of each phase. The method is characterized in that the phases of the stator windings are star-connected at a neutral junction and the voltage pulse is applied to the stator windings of each phase in parallel.

Abstract: A motor drive inverter control apparatus includes a rectifier circuit for rectifying an AC power supply, an inverter circuit driven by an output from the rectifier circuit, a motor driven by an output from the inverter circuit, a first capacitor coupled in parallel to the output of the rectifier circuit, and a second capacitor coupled in parallel to the first capacitor via a diode. The second capacitor has capacitance not less than three times that of the first capacitor. Although the second capacitor shows a ripple content not less than 90% during practical use, it well absorbs regenerative energy produced by the motor. As a result, elements of the apparatus can be prevented from degrading caused by an over-voltage, and the apparatus can be downsized and reduced its cost.

Abstract: A system controls an induction motor driven by a power inverter circuit. An operational amplifier circuit is operatively connected to the power inverter circuit and operative therewith for sensing DC current and controlling acceleration and deceleration of the induction motor. The operational amplifier circuit includes a first operational amplifier operative in a motoring mode to have a positive polarity output and remain substantially at zero during a regeneration mode. A second operational amplifier circuit is operative in a regeneration mode to have a negative polarity output and remain substantially at zero in a motoring mode.

Abstract: A battery pack includes a setting information storage device for storing setting information for setting the functions of an electronic device; a setting information control device for controlling, in accordance with a control signal for the electronic device, processes for writing and reading the setting information to and from the setting information storage device; and a communication device for transmitting and receiving the setting information, which is controlled by the setting information control device via the communication terminal. The electronic device includes a setting information operation device for controlling operations for writing and reading the setting information to and from the storage device of the battery pack; and a communication device for transmitting and receiving, via a communication terminal, the setting information, which is operated by the setting information operation device.

Abstract: A battery management system for managing a plurality of subsystem circuits and functions of a mobile communication device powered by a battery is disclosed. The battery management system includes a battery monitoring circuit, a user interface, and a battery management module. The battery monitoring circuit is operable to monitor a present battery capacity and generate a battery capacity signal based on the present battery capacity. The user interface is operable to receive a user-input allocation of battery capacity among the subsystem circuits and functions. The battery management module is operable to receive the user-input allocation and the battery capacity signal, and to selectively disable each subsystem circuit or function when each subsystem circuit or function has depleted its allocation of battery capacity.

Abstract: A state of charge control system and method uses a region of voltage linearity and a long-term average voltage to estimate an average battery state of charge for storage batteries and to eliminate errors due to hysteresis, drift and sensor noncompliance. An average state of charge Sn is calculated using a current integral method and an average state of charge Sv based on an average observed voltage Vn for a time period exceeding a predefined minimum time but before a predefined maximum time has elapsed is also calculated. If the absolute value of the difference between the Sv and Sn are not are within an acceptable error band, then an offset value is calculated to correct the Sn by subtracting the Sv from the Sn, and thus, to maintain a more accurate Sn. Additionally, a closed current integral method is used to reduce errors due to hysteresis.

Abstract: A wind powered turbine with low voltage ride-through capability. An inverter is connected to the output of a turbine generator. The generator output is conditioned by the inverter resulting in an output voltage and current at a frequency and phase angle appropriate for transmission to a three-phase utility grid. A frequency and phase angle sensor is connected to the utility grid operative during a fault on the grid. A control system is connected to the sensor and to the inverter. The control system output is a current command signal enabling the inverter to put out a current waveform, which is of the same phase and frequency as detected by the sensor. The control system synthesizes current waveform templates for all three-phases based on a sensed voltage on one phase and transmits currents to all three-phases of the electrical system based on the synthesized current waveforms.

Abstract: A system and method are provided for actively reducing ripple in a supply voltage provided by a switched mode power supply. In general, active ripple reduction circuitry operates to sense the ripple in the supply voltage to provide a signal indicative of the ripple. The signal indicative of the ripple is inverted and provided to the output of the switched mode power supply to substantially reduce or eliminate the ripple in the supply voltage.

Abstract: For a PWM controller chip in a voltage converter to switch a pair of high side and low side switches connected with a phase node therebetween, a circuit comprises a sense resistor connected between a multi-function pin on the PWM controller chip and the phase node, and an enable arrangement, a power sensing arrangement, and an over-current protection arrangement to detect the voltage on the multi-function pin for accomplishing enable function, power sensing, and over-current protection, respectively.

Abstract: Voltage regulators often have coupled output inductors because coupled output inductors provide improvements in cost and efficiency. Coupled inductors are often used in multi-phase voltage regulators. Feedback control of voltage regulators often requires accurate and responsive sensing of output current. Provided is a technique for accurately sensing the magnitude of output current in coupled inductors. An RC circuit (comprising a resistor and capacitor in series) is connected in parallel with the coupled inductor. The inductor has a leakage inductance Lk and a DC (ohmic) resistance of DCR. The resistor and capacitor are selected such that an RC time constant is equal to an L/R time constant of Lk/DCR. With the matching time constants, a sum of voltages on the capacitors is accurately proportional to a sum of currents flowing in the output inductors. Also provided is a technique for sensing current when an uncoupled center tap inductor is present.

Abstract: A two-step DC-to-DC converter comprises a first converter stage for converting a first voltage to a second voltage, and a second converter stage for converting the second voltage to an output voltage. The first converter stage uses a MOSFET or normally-off JFET to serve as a high-side switch, and the second converter stage comprises a multi-phase modulator using a normally-on JFET to serve as a high-side switch, thereby improving the efficiency of the two-step DC-to-DC converter.

Abstract: A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.

Abstract: A ripple converter includes a transistor for switching an input direct-current voltage, a choke coil and a smoothing capacitor for smoothing the switched direct-current voltage, a flywheel diode for causing a current to flow through the choke coil when the transistor is turned off, and a comparing unit for controlling the ON/OFF of the transistor according to ripple in an output voltage. In the ripple converter, a waveform converter is provided on a connecting path between an output terminal and a non-inverting input terminal of a comparator in the comparing unit. A result of converting the waveform of the output voltage is compared with a reference voltage, and a result of the comparison is fed back to the transistor.

Abstract: A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.

Abstract: A power supply system is provided, having: a primary side coil; a power transmission apparatus having a primary side circuit for feeding a pulse voltage resulted from switching a DC voltage which is obtained by rectifying and smoothing a commercial power supply to the primary side coil; a secondary side coil magnetically coupled to the primary side coil; and power reception equipment having a secondary side circuit for rectifying and smoothing voltage induced across the secondary side coil, wherein there is provided a power adjusting section for adjusting a level of power to be transmitted according to power required by the power reception equipment.

Abstract: An exciter ring assembly to detect rotational parameters of an axle within a tube has an exciter ring attached to the axle by an elastomer insert. The insert provides a frictional interference fit with the axle. The insert affixes the exciter ring to rotate with the axle. The elastomer insert is supplied with radially-spaced axial channels to enable oil flow past the assembly. The outer member of the assembly is press fit into the axle tube. The outer member remains stationary with respect to the axle tube. The outer member restricts the axial movement of the exciter ring and enables rotation of the exciter ring and provides oil flow across the exciter ring assembly.

Abstract: An angular position sensor including a magnetic field generator means and a magnetic sensor means. The magnetic field generator means produces a magnetic field. The magnetic sensor means has a first magnetic sensor element, a second magnetic sensor element, and a third magnetic sensor element each for providing an output signal depending on a direction of the magnetic field. One of the magnetic field generator means and the magnetic sensor means rotates in conjunction with the target object. The magnetic sensor elements are located so as to provide output signals having different phase differences by allowing the magnetic sensor means to rotate relative to the magnetic field generator means. The magnetic sensor elements are also located such that an output signal of each magnetic sensor element has a phase different from an inverted phase of an output signal of the other two magnetic sensor elements.

Abstract: A linear variable transformer, or LVDT, for use with the transducer, which has a non-ferromagnetic core that can eliminate Barkhausen noise. By eliminating the Barkhausen noise, the sensitivity of the resulting measurements can be improved. The LVDT is formed of multiple coil assemblies which are moved relative to one another, and by using a non-ferromagnetic material, are capable of obtaining 1 ? resolution or better. Circuitry for obtaining a synchronous output is described, allowing a differential amplifier to synchronize one signal to another.

Abstract: Manufacture of a speed sensor, including a cable (15) containing electrical wires for connection between the sensor and a data processing unit, pins joined to the wires and to connection blades of a member for detecting the rotation speed of the wheel of the vehicle, a first molded plastic casing portion (3), having a shaft (13) molded around one end of the wires of the cable, and a cavity in which the pins and the detection member are placed, the pins being mutually separated and the wires being mutually separated at the point of their stripped end, and the detection member being held in place in the cavity of the first casing portion by retaining lugs made of one piece with this first casing portion, and a second casing portion (5) including a part that isolates the pins and the detection member from the outside.

Abstract: A planer reader and method of probing the magnetic permeability of a material using a magnetic flux circuit comprises a substrate; a near-circular soft magnetic layer adjacent to the substrate; a gap configured in the soft magnetic layer, wherein the gap creates an opening between two ends of the soft magnetic layer, and wherein the gap is configured to align with a material located a distance from the soft magnetic layer; a magnetic flux generator adapted to provide magnetic flux to the material; and a magnetic sensor adapted to measure the magnetic flux traversing the material. The circuit further comprises an insulator covering the soft magnetic layer, the gap, the magnetic flux generator, and the magnetic sensor. The magnetic flux generator comprises a magnet or a magnetic coil proximate to the soft magnetic layer. Moreover, the soft magnetic layer comprises a soft ferromagnet. In one embodiment, the substrate is flexible.

Abstract: Systems, methodologies, media, and other embodiments associated with a block-by-block off-resonance frequency estimation method are described. One exemplary method embodiment includes calculating a field map from local B0 off resonance frequency estimates. The example method may also include performing water-fat decomposition and signal de-blurring based on the calculated map.

Abstract: Methods and Systems for image reconstruction in magnetic resonance imaging (MRI) are provided. The method includes receiving MRI data and storing the received MRI data. The method further includes reordering the stored MRI data during an image reconstruction.

Abstract: In a method for magnetic resonance imaging, whereby magnetic resonance signals in a region of interest of an examination subject are generated in an examination by applying radio-frequency pulses of a first transmission field strength and the magnetic resonance signals are acquired in a spatially coded manner and allocated to volume elements of the region of interest in order to obtain one or more magnetic resonance images of the region of interest, the sensitivity of each volume element of the region of interest with respect to a modification of the first transmission field strength is determined, deviations of the first transmission field strength from a reference field strength are measured during the examination, and the magnetic resonance signals acquired in the examination are corrected on the basis of the sensitivity determined for each volume element and on the basis of the measured deviations of the first transmission field strength from the reference field strength.

Abstract: The subject invention pertains to a method and apparatus utilizing one or more spiral coils, such as spiral birdcage coils, spiral saddle coils, Helmholtz coil pairs, and other spiral volume and spiral surface coils. The spiral coils of the subject array can be substantially isolated from each other while covering nearly the same volume or surface. For cylindrical geometrics, isolation can be enhanced by having the rotation, or change in direction from one end of the coil to the other, be 2n?, where n is an integer.

Abstract: A sheath wave barrier unit for an outer shielding of a coaxial cable that also has an inner conductor, has two sheath wave barriers that damp or suppress sheath waves that are induced in two series conductor segments of the outer shielding. Each sheath wave barrier forms a resonant oscillating circuit at a predetermined high frequency, with the high frequency being the same for both sheath wave barriers. The sheath wave barrier unit has a shielding device with at least one radial shield by means of which the sheath wave barriers are decoupled from one another. The sheath wave barriers and the shielding device are arranged on a common carrier.

Abstract: Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.

Abstract: A method of diagnosing failure of fuel level sensors includes a first measuring step of measuring voltages from first and second failure detection terminals; if the voltage is higher than a reference, diagnosing the voltage as “high,” and if the voltage is lower than a reference, diagnosing the voltage as “low;” and if the voltage is neither high nor low: a second measuring step of receiving the voltages from the first and second failure detection terminals; calculating and storing a difference between the voltages of the first and second failure detection terminals; determining whether an amount of fuel is reduced; if the amount of fuel is reduced, calculating a difference between voltage signals of the first and second failure detection terminals; determining whether the voltage difference before and after the amount of fuel was reduced are identical; and if the voltage differences are identical, returning to the first measuring step.

Abstract: A circuit and method for judging a latent short-circuit defect, also known as a short-circuit defect with time passing, in the case of a high voltage system. A detection-dedicated wiring for detecting a short-circuit defect is provided between a first high voltage system wiring and a second high voltage wiring. A power supply and an ammeter is connected in series and one end of it is connected to the high voltage system wiring and the other end of it is connected to the detection-dedicated wiring. If a current value us higher than a predetermined value when the power supply is turned on, one can judge that the circuit has a high possibility of the latent short-circuit defect.

Abstract: A method and system for determining a location of a phase-to-earth fault in a line of an electric network, the electric line comprising two or more sections (30a, 30b, 30c), the system being configured to determine, at a measuring point, a reactance of a fault loop; determine a faulted section of the electric line to be a section closest to the measurement point of all such sections for which a sum of a positive sequence reactance and an earth return path reactance of the section in question and positive sequence reactances and an earth return path reactances of sections, if any, between the measurement point and the section in question is greater than or equal to the determined reactance of the fault loop; and calculate a distance between the measuring point and a point of fault on the basis of the reactance values.

Abstract: A proximity sensor module includes a housing; and a proximity sensor disposed in the housing, wherein the proximity sensor comprises a sensor plate configured to contact inside of the housing such that substantially no gap exists between the sensor plate and the housing. The housing may be a substantially explosion-proof housing. The housing may include two members coupled by a thread engagement, wherein a sensor plate of the proximity sensor is placed off-center with respect to an axis of rotation for the thread engagement.

Abstract: The invention provides an electrooptic device and an electronic apparatus, in which the electrical characteristics of many thin-film switching elements formed in a substrate to support an electrooptic material can be accurately inspected. The invention also provides a method for making the electrooptic device. In a TFT array substrate of a liquid crystal device, an inspection TFT is formed in one of dummy pixels disposed at the periphery of a pixel region. A pixel electrode connected to a drain region of the TFT functions as a first inspection pad. In an adjacent dummy pixel, the pixel electrode electrically connected to an extended portion of a data line functions as a second inspection pad. In another adjacent dummy pixel, the pixel electrode electrically connected to an extended portion of a scan line via a junction electrode functions as a third inspection pad.

Abstract: A plurality of probes such as a signal probe (3) and a power supply probe (4) are provided into a metal block (1) so as to penetrate. Each of the probes has a movable pin (11). A tip of the movable pin is projecting from one surface of the metal block (1). And a projection length of the tip is variable. A DUT 20 is pressed onto the surface of the metal block (1) to contact between electrode terminals (21 to 24) and tips of the probes to test characteristics of the DUT. At least one of the probes is capacity loaded probe having a capacitor by providing a dielectric layer and a metal film to peripheral of the probe. As a result, noise can be removed reliably. Additionally, when the capacity loaded probe is used as the power supply probe, a voltage drop is reduced at the power supply terminal in a case of change of the output.

Abstract: A test board for a high-frequency system level test: The test board includes a main board having through holes filled with a conductive material. These holes may be located at a portion of the main board from which an existing module socket has been removed. An interface board has surface mounted device (SMD) pads on front and rear surfaces. The SMD pads on the front surface of the interface board are connected with the SMD pads on the rear surface thereof through cross connection wiring within the interface board for a pin swap. The through holes of the main board are connected with the SMD pads on the rear surface of the interface board via iron cores fixed at a guide. A test module socket is mounted on surfaces of the SMD pads on the front surface of the interface board.

Abstract: An electrical component testing device comprising a housing having at least one recess covered by a flexible membrane so as to form a chamber. A fluid passage extends through a portion of the housing and connects to the chamber thus permitting passage of a fluid material into the chamber. At least one contact member is positioned on the flexible membrane so as to provide an electrical connection to an electrical contact on a device to be tested.

Abstract: Apparatuses and methods for testing electronic components, such as printed circuit boards, in an ergonomic manner are disclosed. An electronic component testing apparatus comprises a base, a test chamber rotatably mounted to the base, and a heating and cooling unit coupled to the test chamber. The test chamber further includes a chassis defining an enclosure having an opening and at least one test slot accessible through the opening for facilitating operative coupling of an electronic component to the test chamber for testing of the electronic component.

Abstract: The present invention relates to a probe for testing of integrated circuits or other microelectronic devices.

Abstract: An integrated circuit and an associated packaged integrated circuit are provided which improve testability and reduce the test costs. The integrated circuit contains an integrated functional circuit to be tested, a test interface that connects the functional circuit to a test apparatus which performs a function test on the functional circuit to ascertain a test result, and an integrated self-marking apparatus that produces a marking on the basis of the test result. The marking can be magnetic or optical or electrical, volatile or nonvolatile, and thermally or electrically activated. The test apparatus includes an external test unit or an integrated self-test unit. Nonvolatile memory elements store the test results in a buffer.

Abstract: Systems for testing a plurality of integrated circuits at a plurality of frequencies and voltages is disclosed. In one embodiment, a plurality of integrated circuits is tested at least once within a predetermined set of combinations of frequencies and voltages. If the integrated circuit fails testing within any combination of a frequency and voltage within the predetermined set, the integrated circuit is retested at a different predetermined set of combinations of frequencies and voltages. If the integrated circuit fails testing within any combination of a frequency and voltage within the different predetermined set, the integrated circuit is discarded.

Abstract: A method includes providing an integrated circuit (IC) having a plurality of oscillators at distributed locations in the IC, determining a respective rate of oscillation of each of the oscillators, and detecting variations in local temperature in the IC based on the determined rates of oscillation. Other embodiments are described and claimed.