691 results about "Forward current" patented technology

A vehicle lighting system for a vehicle includes an accessory module assembly that is adapted for attachment to an interior portion of a vehicle and configured to illuminate, for example, an area inside the vehicle. The module assembly includes a single high-intensity power light emitting diode that has a luminous efficiency of at least about 1 lumen per watt when the light emitting diode is operated and is preferably operated at a forward current of at least 100 milliamps. The system also includes a voltage conversion element for converting the battery / ignition voltage of the vehicle to the forward operating voltage of the light emitting diode.

The present invention is directed to an LED lighting source comprising a housing adapted for coupling to an AC power source; a rectifier circuit for converting the AC power to a DC supply; a power control circuit disposed in the housing and electrically connected to the DC supply; a string of LED's electrically connected between a control node of the power control circuit and the DC supply, the LEDs in the string being connected in series and being of a number selected to produce a voltage difference across the power control circuit sufficient to power active components of said power control circuit when powered from the DC supply and the power control circuit for limiting a forward current through the string to a nominal forward current of a single LED.

In a drive device for an active type light emitting display panel which can apply a reverse bias voltage to an EL element, in order to be able to compensate deterioration in light-emitting efficiency of the EL element accompanied by applying of the reverse bias voltage and the like, one pixel 10 is composed of a controlling TFT (Tr1), the driving TFT (Tr2), a capacitor C1, and the EL element E1. Switching switches SW1, SW2 mutually enables a supplying state of a forward current to the EL element E1 and an applying state of the reverse bias voltage to be selected. In one control form according to the present invention, when the applying state of the reverse bias voltage shifts to the supplying state of the forward current, by switching one switch first, the anode and cathode of the EL element E1 are made to the same electrical potential to allow electrical charges to be discharged. Thus, charge of the forward current for a parasitic capacitance of the EL element E1 can be performed rapidly, and rising of the lighting operation of the EL element can be advanced.

Illumination of a portion of a vehicle interior is provided by an interior rearview mirror assembly incorporating a solid-state light source comprising a light emitting diode (LED) which emits light generally downwardly from the assembly. In one form of the invention, the mirror case of the rearview mirror assembly includes at least one of an opening, a light conduit, and a fiberoptic element through which the LED emits light. In another form, the LED preferably has a luminous intensity of at least 500 mcd when operated at a forward current of 20 mA. The LED preferably has a dominant wavelength of at least about 530 nm. The light emitted by the LED may be selected from green, orange, yellow, amber, reddish-orange, red and blue. The vehicle interior portion may include at least one of a shift lever console and a floor console.

The present invention provides a system and method for controlling one or more light-emitting elements which are driven by forward currents to generate mixed light for use, for example, through a luminaire. The system has one or more light sensors for acquiring feedback optical sensor data and a user interface for providing reference data representative of a desired mixed light. The system also has a controller for transforming either the sensor data or the reference data into the coordinate space of the other and to determine a difference between the sensor and the reference data in that coordinate space. The controller is configured to adjust the forward currents during operating conditions so that the sensor data matches the setpoint data. The present invention also provides a system and method that can at least partially compensate certain temperature induced effects when transforming the optical sensor or the reference data.

A system, apparatus, and method for allowing LED operation in circuits operating with power supply levels that are below the forward voltage limits of the LED. A first level of a modulated voltage signal is applied to charge a voltage increasing component in a first phase of operation. A second level of the modulated voltage signal is then summed with the voltage stored across the voltage increasing component to provide adequate forward potential across Light Emitting Diode (LED) for illumination. The second level of modulated voltage is also used to provide a source of constant forward current to be conducted by LED when in its luminescent state.

Owing to the property of bidirectional conduction under the saturation mode, synchronous rectifiers in conventional power converters usually suffer from a reverse current under light loads or a shoot-through current under heavy loads. The reverse current may degrade the converter efficiency and the shoot-through current may damage synchronous rectifiers. The present invention discloses a unidirectional metal oxide semiconductor field effect transistor (UMOS), which comprises a metal oxide semiconductor field effect transistor (MOS), a current detection circuit and a fast turn-off circuit. The current detection circuit detects the direction of the current flowing through the MOS. When a forward current is detected, the fast turn-off circuit is disabled and the channel of the MOS can be formed. When a reverse current is detected, the fast turn-off circuit is enabled and the channel of the MOS cannot be formed. This UMOS can be applied, but not limited, to synchronous rectifiers to detect the occurrence of a reverse current or a shoot-through current and fast turn off the channel of the MOSFET.

A JFET controlled Schottky barrier diode includes a p-type diffusion region integrated into the cathode of the Schottky diode to form an integrated JFET where the integrated JFET provides on-off control of the Schottky barrier diode. The p-type diffusion region encloses a portion of the forward current path of the Schottky barrier diode where the p-type diffusion region forms the gate of the JFET and the enclosed portion of the forward current path forms the channel region of the JFET. By applying a reverse biased potential to the gate of the JEFT with respect to the anode of the Schottky diode, the forward current of the Schottky diode can be pinched off, thereby providing on-off control over the Schottky diode forward current.

The present invention provides a system and method for controlling one or more light-emitting elements which are driven by forward currents to generate mixed light for use, for example, through a luminaire. The system has one or more light sensors for acquiring feedback optical sensor data and a user interface for providing reference data representative of a desired mixed light. The system also has a controller for transforming either the sensor data or the reference data into the coordinate space of the other and to determine a difference between the sensor and the reference data in that coordinate space. The controller is configured to adjust the forward currents during operating conditions so that the sensor data matches the setpoint data. The present invention also provides a system and method that can at least partially compensate certain temperature induced effects when transforming the optical sensor or the reference data.

Provided is a via for use in a printed circuit board or integrated circuit having first, second, third, and fourth layers. The via includes a first path capable of transmitting a forward current from the first to the second layer and a second path capable of transmitting a return current resulting from the forward current from the third to the fourth layer to return to a source of the forward current.

A variable resistive memory device includes a main wordline, a wordline connecting switch in signal communication with the main wordline, a sub-wordline in signal communication with the wordline connecting switch, and a variable resistive memory cell having a variable resistance in signal communication with a first terminal of a switching element, a second terminal of the switching element disposed in signal communication with the sub-wordline; and a method of controlling the voltage of a sub-wordline in a variable resistive memory device includes switchably passing a voltage from a main wordline to the sub-wordline, and substantially blocking forward current flow from the sub-wordline to a variable resistive memory cell of the device.

A light emitting device having a circuit protection unit is provided. The circuit protection unit has a low-resistance layer and a potential barrier layer, wherein a barrier potential exists at the interface between the low-resistance layer and the potential barrier layer. The circuit protection unit is electrically connected with the light emitting device. When an electrostatic discharge or excessive forward current is occurred in the light emitting device, the circuit protection unit provides a rectifying function for preventing damages caused by static electricity or excessive forward current to the light emitting device.

A DC matrix converter having six forward current conducting power switches and six reverse current conducting power switches has the on time duration of each power switch within each pulse width modulation period controlled by relationships between d, q components of a modulation index determined by the ratio of a voltage command to the instantaneous voltage of the AC mains expressed in stationary d, q coordinates, the selection of which is made based on inequalities between the AC mains voltage components expressed in dq coordinates, and relationships of the AC main voltage components expressed in d, q coordinates. Zero vectors are related to the one AC main having lower line-to-neutral voltage than the other AC mains, using relationships between the instantaneous AC mains voltage in d, q coordinates.

Excessive evolution of hydrogen in electrolytic deposition of metals on a cathode substrate can be controlled by using a pulsed reverse current. Reverse current pulses interposed between the forward current pulses consume at least some of the nascent hydrogen and prevent the local pH at the cathode surface from becoming excessively alkaline. Control of hydroxide ion concentration by pulsed reverse current alleviates problems caused by reaction of metal-bearing-ions with hydroxide ions generated near the cathode by evolution of hydrogen. The method is useful in depositing functional chromium coatings on electrically conductive substrates from plating baths comprising aqueous solutions of trivalent chromium salts. In such a method the current comprises forward pulses having a duty cycle of from about 50% to about 90% and reverse pulses having a duty cycle of from about 5% to about 30%, and a frequency of from about 5 Hz to about 700 Hz.

A power diode having a silicon mesa atop the drift region includes a first contact positioned on the silicon mesa. The silicon mesa is highly doped p-type or n-type, and the anode may be formed on the mesa. The mesa may include two separate silicon layers, one of which is a Schottky barrier height layer. Under a forward bias, the silicon mesa provides carriers to achieve desirable forward current characteristics. The substrate has a significantly reduced thickness. The diode achieves reverse voltage blocking capability by implanting junction barrier Schottky wells within the body of the diode. The diode utilizes a deeper portion of the drift region to support the reverse bias. The method of forming the diode with a silicon mesa includes forming the mesa within a window on the diode or by thermally or mechanically bonding the silicon layer to the drift region.

A pulse oximeter with drive lines for driving red and IR LEDs, and a drive circuit for driving those drive lines. A processor controls the drive circuit using a red zero output line and an IR zero output line directly connected between the processor and the drive circuit. This allows a control signal to directly control the turning off of either the red or IR drive transistors to prevent forward current flow through the red and IR LEDs by overriding the ongoing programmable logic state machine control of the drive transistors. The effects of crosstalk and capacitive coupling are reduced as a result.

An instrument measures the LED junction temperature directly by taking advantage of the linear relationship between the forward current driven through the LED, the forward drop of the LED, and the junction temperature to determine the LED junction temperature.Calibration is conducted by placing two LEDs from the same family in ambient temperature and passing a small test current through each of the LEDs to obtain the forward drop of the LED at ambient temperature. The LED under test is then placed in an environmentally-controlled chamber where the temperature is raised a known amount above ambient temperature. Known low and high voltage values are associated with the ambient temperature and the environmental chamber temperature, causing the LED under test becomes a calibrated thermometer that can measure its own junction temperature due to the linear relationship between the forward drop and the junction temperature.

The invention relates to a high-precision and constant temperature and humidity cabinet, which is used for storing special articles. The temperature and humidity in the cabinet can be controlled within designated scope automatically and constantly. In the invention, a cooling / heating semiconductor high-temperature stacking is used as a temperature control and dehumidification executive component, an ultrasonic wave humidifier is used as a humidification executive component, and an electric temperature / humidity sensor, a series of fans, keys, a display, a controller and the like are mounted, thereby realizing constant temperature and humidity. When temperature inside the cabinet is higher than preset target temperature, the temperature control semiconductor high-temperature stacking generates forward current to reduce the temperature inside the cabinet; when temperature inside the cabinet is lower than the preset target temperature, the temperature control semiconductor high-temperature stacking generates reverse current to raise the temperature inside the cabinet to the preset target temperature; when humidity inside the cabinet is higher than preset target humidity, the dehumidification semiconductor high-temperature stacking generates forward current to reduce the temperature of a condensation block in the cabinet to be below the dew point, so as to enable moisture in the cabinet to condensate and flow into a water tank to realize dehumidification effect; and when humidity inside the cabinet is lower than preset target humidity, an ultrasonic wave humidifier sprays water mist to raise the humidity in the cabinet to the preset target humidity.

The object of the invention is to provide an organic electroluminescent display device and driving method including an apparatus comprised of at least one organic-light-emitting diode (OLED), a rectification diode and a capacitor used as a memory device. A frame period of the display device is divided into sub-frames, which have address and light emission periods. Current mode data programming is used to address the display device in each sub-frame. In the light emission period, charge previously stored in selected capacitors during the address period, supplies the forward current for the OLEDs. A ramp waveform applied to the row electrode, during the light emission period, forces the capacitor to discharge through the OLED and controls the forward current level. The operation of the OLEDs are retained in their area of maximum performance.

A control circuit for a synchronous rectification switching regulator including an output terminal, a switching transistor, an inductor, and a synchronous rectification transistor has a control part configured to control switching of the switching transistor to charge the inductor to and set a voltage output from the output terminal to a predetermined voltage, which causes the synchronous rectification transistor to switch reversely to the switching transistor and discharge the inductor, and backflow prevention part configured to block a current flowing in the synchronous rectification transistor to prevent a backflow current that flows in a direction from the output terminal to the synchronous rectification transistor. The backflow prevention part detects a forward current and regulates timing to block the current flowing in the synchronous rectification transistor and to regulate a time period from blocking the current flowing in the synchronous rectification transistor to determining that the forward current is zero.

Disclosed herein is a voltage judgment circuit comprising one or more diodes inserted in the forward direction of a judgment voltage, a current extraction section for extracting a forward current of the diodes, and a comparison section for comparing an output current from the current extracting section with a specified current value to input the comparison results. According to the voltage judgment circuit of the present invention, the discharge after the charging can be prevented to perform the voltage judgment using a low consumption current with high accuracy. A battery cell pack having the above voltage judgment circuits also performs a similar judgment.

Provided is a device for driving an active matrix type luminescent display panel, which can effectively apply a reverse bias voltage to a luminescent element via a drive TFT. A luminescent element 14 constituting one pixel 10 is light-up driven by a control TFT 11 and a drive TFT 12. A serial circuit of the drive TFT 12 and the luminescent element 14 is connected to a power source circuit via a switch S1 and a switch S2, whereby a state where a forward-directional current is supplied to the luminescent element or a state where a reverse bias voltage is applied to the luminescent element is selected. By using, as the control TFT 11 and the drive TFT 12, TFT of the channel type of that is the same, it is possible to maintain the drive TFT 12 to be in an “on” state when having applied a reverse bias voltage to the luminescent element 14. By doing so, it becomes possible to effectively apply a reverse bias voltage to the luminescent element.

A method of controlling a switching mode power converter enables zero voltage switching by forcing a voltage across the main switch to zero. This is accomplished by sensing when a current on the secondary side of the power converter drops to zero, or other threshold value, and then generating a negative current through the secondary winding in response. The negative secondary current results in a corresponding discharge current in the primary winding, which reduces the voltage across the main switch. The voltage across the main switch is monitored such that when the voltage reaches zero, or other threshold value, the main switch is turned ON. In this manner, the circuit functions as a bi-directional current circuit where a forward current delivers energy to a load and a reverse current provides control for reducing the voltage across the main switch to enable zero voltage switching.

A circuit for detecting an electric current by which a loss portion of a forward current caused by a backward leakage current of a diode generated by the influence of temperature increase can be compensated such that error in the peak value of a load current detected by surrounding high temperature can be minimized, and credibility reliability can be increased for electric instruments that call for an accurate control of the load current and that generate a high temperature such as induction heating cookers, induction heaters and the like.

A power supply for a capacitive-resistive load includes plural paralleled phase correcting modules together with current sharing controllers for tending to equalize their currents. Each module is provided with a diode, poled to prevent forward current from flowing in the return current path, for aiding in equalizing module currents. Surge currents are reduced by a single saturable reactor coupled to the combined outputs of current sharing controllers, thereby avoiding the need for soft-start in each controller. A precharging path extends from a source of pulsating direct voltage to the load, for precharging the load capacitance at turn-on.

In a drive device for an active type light emitting display panel which can apply a reverse bias voltage to an EL element, in order to be able to compensate deterioration in light-emitting efficiency of the EL element accompanied by applying of the reverse bias voltage and the like, one pixel 10 is composed of a controlling TFT (Tr1), the driving TFT (Tr2 ) , a capacitor C1, and the EL element E1. Switching switches SW1, SW2 mutually enables a supplying state of a forward current to the EL element E1 and an applying state of the reverse bias voltage to be selected . In one control form according to the present invention, when the applying state of the reverse bias voltage shifts to the supplying state of the forward current, by switching one switch first, the anode and cathode of the EL element E1 are made to the same electrical potential to allow electrical charges to be discharged. Thus, charge of the forward current for a parasitic capacitance of the EL element E1 can be performed rapidly, and rising of the lighting operation of the EL element can be advanced.

A nonvolatile memory device includes at least one memory cell which comprises a diode and a metal oxide antifuse dielectric layer, and a first electrode and a second electrode electrically contacting the at least one memory cell. In use, the diode acts as a read / write element of the memory cell by switching from a first resistivity state to a second resistivity state different from the first resistivity state in response to an applied bias.