793 results about "Threshold current" patented technology

An information processor of a high reliability and a high recording density, and a blue color, blue-violet color and violet color based semiconductor light emitting device operable at a low threshold current density, used for the same, are provided. An optical information processor of a high reliability and a high recording density enables a moving picture, such as a high-definition television picture, to be recorded and reproduced satisfactorily. A barrier layer in a quantum-well active layer of a semiconductor light emitting device is doped with n-type impurities at a high density. Alternatively, the face orientation of a quantum-well active layer of a semiconductor light emitting device is a plane inclined from the (0001) plane, whereby the threshold current value of the semiconductor light emitting device can be decreased. The semiconductor light emitting device is typified by a gallium nitride based compound semiconductor laser device.

We describe a photovoltaic power conditioning unit for delivering power from multiple photovoltaic panels to an ac mains power supply output, comprising: a dc input for receiving power from multiple photovoltaic panels; an ac output for delivering ac power to the ac supply; a bank of electrolytic energy storage capacitors for storing energy from the dc source for delivery to the ac supply; a dc-to-ac converter coupled to the ac output and having an input coupled to the bank for converting energy stored in the bank to ac power for the ac supply; and further comprising: a plurality of sense and control circuits, one for each capacitor in the bank, wherein each circuit is coupled in series with a capacitor, and is configured to disconnect the associated capacitor from the bank upon detection of a current flow through the associated capacitor of greater than a threshold current value.

An edge emitting solid state laser and method. The laser comprises at least one AlInGaN active layer on a bulk GaN substrate with a non-polar or semi-polar orientation. The edges of the laser comprise {1 1−2±6} facets. The laser has high gain, low threshold currents, capability for extended operation at high current densities, and can be manufactured with improved yield. The laser is useful for optical data storage, projection displays, and as a source for general illumination.

An access point in an optical fiber-based high-speed optical wireless network is disclosed. The access point includes an antenna for receiving communication requirement signals, a switch for selectively outputting a corresponding signal according to the communication requirement signals, a bias control unit for selectively outputting bias current with variable intensity according to whether an output of the signal from the switch exists or not, on the basis of a threshold current; a bias operation unit for outputting input signals to the antenna when an input bias current is smaller than the threshold current and for outputting signals received by the antenna when an input bias current is larger than the predetermined threshold current, and a semiconductor optical amplifier for selectively performing an optical detection function of converting optical signals, which have been received through a first optical fiber from an central station, into electrical signals and sending the converted electrical signals to the bias operation unit, when a current smaller than the threshold current is input to the bias operation unit, and an optical modulation function of transmitting signals output from the bias operation unit through a second optical fiber to the central station, when a current larger than the threshold current is input to the bias operation unit.

A current-triggered synchro-rectifier comprising an electronic switch configured to be in its ON setting when the current flowing through its cathode exceeds a predetermined threshold. The electronic switch may include a half-wave rectifier wired to the source terminal and the drain terminal of a MOSFET device, and a current monitor configured to monitor the drain-current flowing through the drain terminal. The current monitor sends a gate signal to the gate terminal such that the MOSFET is switched to its ON state when the drain-current exceeds a first threshold current and the MOSFET is switched to its OFF state when the drain-current falls below a second threshold current. Usefully, the synchro-rectifier may be incorporated into a full-wave rectifier.

A first resistor is connected in parallel with a second resistor having a lower resistance than the first resistor. The voltage at the terminal of the first resistor is compared with a first threshold voltage, and the voltage at the terminals of the second resistor is compared with a second threshold voltage. A switching device either connects the first resistor in series in a remote power feed circuit, if the switching device detects that the remote power feed current is less than a third threshold current that is between the first and second threshold currents, or connects the second resistor and the first resistor, connected in parallel, in series in the remote power feed circuit if the switching device detects that the remote power feed current is greater than the third threshold current.

We describe a photovoltaic power conditioning unit for delivering power from multiple photovoltaic panels to an ac mains power supply output, comprising: a dc input for receiving power from multiple photovoltaic panels; an ac output for delivering ac power to the ac supply; a bank of electrolytic energy storage capacitors for storing energy from the dc source for delivery to the ac supply; a dc-to-ac converter coupled to the ac output and having an input coupled to the bank for converting energy stored in the bank to ac power for the ac supply; and further comprising: a plurality of sense and control circuits, one for each capacitor in the bank, wherein each circuit is coupled in series with a capacitor, and is configured to disconnect the associated capacitor from the bank upon detection of a current flow thorough the associated capacitor of greater than a threshold current value.

A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.

A control device and method for detecting and controlling a water fill level in a dishwasher or other similar appliance that includes a pump motor is provided. The control monitors the pump motor current over time, determines a current change, and compares the current change to a threshold current change that is indicative of the water level.

A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.

A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.

A current sensor 73 detects a current flowing through a first buss bar 11. When a current value detected by the current sensor 73 became equal to or greater than a threshold current value, a CPU 74 outputs a driving control signal to a driving circuit 77, and the driving circuit 77 operates an, ignitor 29 through a second substrate 65 and a terminal 50. Therefore, the ignitor 29 ignites, a second projection 41 is melted by heat of a heating agent 27, a compression spring 34 is expanded and a thermite case 26 jumps up. Thus, electrical connection between the thermite case 26 and the first and second buss bars 11, 19 is interrupted. Further, since an outer container 61 in which the current sensor 73, the CPU and the driving circuit 77 are accommodated is integrally assembled with the cap 14a and the resin case 14b in which the thermite case 26, the ignitor 29, the compression spring 34 and the second projection 41 are accommodated, non-operational state of the ignitor 29 due to disconnection of electric wire is not generated.

A light-load power transistor and a heavy-load power transistor are connected in parallel between an input voltage and an output voltage. The light-load power transistor has a smaller current driving capability, i.e. a smaller dimension of a current path. During a light-load mode, only is the light-load power transistor activated to reduce the current consumption caused by an error amplifier, thereby enhancing the efficiency. When a detection current signal is higher than a threshold current signal, the heavy-load power transistor is additionally activated through a gate control circuit by a mode selection circuit, thereby achieving a sufficient current driving capability.

A comparator circuit of a temperature sensor includes an output node and a variable current node. The output node is a first voltage at a given temperature when a current at the variable current node is less than a threshold current, and a different second voltage at the given temperature when the current at the variable current node is more than the threshold current. A variable resistance circuit includes at least n resistors of different resistive values connected in series between the variable current node of the comparator and a supply voltage, where n is an integer of 4 or more. A switching circuit is provided to selectively bypasses individual ones of the n resistors during a test sequence to determine a trip temperature of the sensor.

A light-load power transistor and a heavy-load power transistor are connected in parallel between an input voltage and an output voltage. The light-load power transistor has a smaller current driving capability, i.e. a smaller dimension of a current path. During a light-load mode, only is the light-load power transistor activated to reduce the current consumption caused by an error amplifier, thereby enhancing the efficiency. When a detection current signal is higher than a threshold current signal, the heavy-load power transistor is additionally activated through a gate control circuit by a mode selection circuit, thereby achieving a sufficient current driving capability.

A resistive superconducting fault current limiter comprises: a superconducting limiter element which is in a superconductive state in the event of a normal current occurrence, and which is in a normal conductive state having a predetermined resistance when a fault current larger than a predetermined threshold current value flows; a superconducting serial coil serially connected to the superconducting limiter element so as to face each other so that a current loss can be minimized accordingly as currents flow in opposite directions thus to cancel magnetic fields, and having a threshold current value greater than the threshold current value of the superconducting limiter element by a predetermined ratio; and a normal conductor parallel coil connected to the superconducting limiter element in parallel and having a predetermined resistance smaller than the resistance of the superconducting limiter element when a fault current occurs, for preventing the superconducting limiter element from being overheated by dividing a current flowing through the superconducting limiter element and for uniformly quenching the superconducting limiter element by generating a magnetic field when a fault current occurs