153results about "Arrangements responsive to underload" patented technology

An electrical safety outlet for accepting a plug to provide power to electrical appliances including a power supply and an intelligent circuitry for controlling the power supply to the electrical outlet; the intelligent circuitry includes circuits for determining temperature condition in the outlet, mechanical plug insertion into the outlet, load presence on the outlet, and current capacity conditions.

An electrical load status detection and control device includes a first power supply circuit loop with a first switch, a second power supply circuit loop with a second switch, a no-load status detection unit connected with the second power supply circuit loop for detecting the current passing through the second power supply circuit loop and thereby generating a current detection signal. A micro-controller connected with a reference current value database, the no-load status detection unit, the first switch and the second switch, which receives the current detection signal from the no-load status detection unit. The micro-controller generates a switching signal to actuate the first switch and the second switch to thereby open the first power supply circuit loop and the second power supply circuit loop when detecting the current passing through the second power supply circuit loop out of the reference current value range of the reference current value database.

Novel circuitry and methodology for detecting a Powered Device (PD) in a system for providing power to the PD. PD detection circuitry detects the PD in a first mode by providing detection current to probe the PD, and in a second mode by providing detection voltage to probe the PD. A control circuit determines that the PD is a valid device if the PD is detected both in the first mode and in the second mode.

There is provided a load detector for determining whether a load is connected to an AC-AC power supply. The power supply comprises a transformer having a primary winding and a secondary winding, the primary winding being coupleable to an AC voltage supply via a switch, and the secondary winding being coupleable to a load. The load detector comprises a signal generator for generating a signal; a sensor for detecting the signal, the sensor being arranged to detect the signal if a load is coupled to the secondary winding and to not detect the signal if a load is not coupled to the secondary winding; and switch control circuitry coupled to the sensor and being arranged to keep the switch closed if the sensor is detecting the signal and to keep the switch open if the sensor is not detecting the signal. There is also provided an AC-AC power supply comprising such a load detector.

An apparatus supplies AC power to a load. The apparatus includes a set output terminals, a primary circuit, and a load sensing circuit. The primary circuit is electrically coupled to a source of AC power and to the output terminals for selectively providing power at a low voltage at the output terminals or electronically coupling the source of AC power directly to the output terminals. The load sensing circuit coupled to the primary circuit and the source of AC power for determining a resistance associated with the load at initial application of the load and controlling the primary circuit to electronically couple the source of AC power directly to the output terminals if a proper load is detected.

A standby power consumption limiting device is provided for connection between an electricity supply and an electrical appliance of the kind having a main on/off switch, two power supply input terminals and a standby mode control circuit operable, when the appliance is switched “on”, to place the appliance in a reduced power standby mode. The device comprises standby mode detection means (102,103) effective to detect and indicate that the appliance has gone into standby mode and power switching means (104) having a first state in which the electricity supply is connected to the appliance via its power supply input terminals and a second state in which the electricity supply is disconnected from the appliance. A power switch control means (107) responds to an indication from the standby mode, by switching the power switching means from its first state to its second state, thereby removing power from the appliance. At this point, a test signal generating means (105), connected to one of the appliance input terminals by the power switching means when in its second state, generates a test signal of predetermined form, said test signal being returned, while the appliance main switch is in the “on” state, via the other appliance input terminal. A test signal detection means (106), connected to said other appliance input terminal by the power switching means when in its second state, is capable of detecting the test signal returned via said other terminal, when the appliance main switch is in its “on” state and of detecting a predetermined change in the returned test signal indicative of the appliance main switch having been turned to its “off” state. The power switch control means is responsive to an indication from the test signal detection means that the appliance main switch has turned been turned “off” to put the power switching means back into its first state thereby restoring power to the appliance which will then become active when its power switch is returned to the on position.

The invention provides a mobile power supply which comprises a singlechip (1), an output control circuit (5), a lithium cell (4) and a heavy current instantaneous output module, wherein the output control circuit (5) is respectively connected with the singlechip (1) and the lithium cell (4), the heavy current instantaneous output module comprises a heavy current output unit (11) connected with the output control unit (5) and a voltage detection wake-up unit (12) connected with the heavy current unit (11), the heavy current output unit (11) is used for being connected with electric equipment, the voltage detection wake-up unit (12) is connected with the singlechip (1) and comprises an electric equipment voltage detection unit (121) used for detecting the voltage of the electric equipment, and the electric equipment voltage detection unit (121) controls the power supply state of the heavy current output unit (11) according to the detected voltage.

A power supply control device for controlling power supply to a pair of terminals to which a load is connected, comprising a voltage measuring part for measuring a voltage which has a predetermined relationship with the voltage of the pair of terminals, a short circuit detecting part for detecting whether a short circuit exists between the pair of terminals based on the measured voltage and for making power supply to the pair of terminals stop when existence of a short circuit is detected, and a constant current supplying part for supplying a constant current though the pair of terminals; wherein the short circuit detecting part is configured to detect that the previously detected short circuit is eliminated when the voltage measured by the voltage measuring part is equal to or greater than a predetermined threshold value upon supplying the constant current through the pair of terminals.

Power switching apparatus comprising switch means having a control terminal and output terminals for connection in series between a power supply and a load. The switch means is responsive to a control signal applied to the control terminal to switch between an ON-state in which it supplies power supply current from the power supply through the output terminals to the load and an OFF-state in which it interrupts the supply of power through the output terminals to the load. The apparatus includes detection means for detecting an open-load condition of the load at least during the ON-state of the switch means, comprising detection control means operable in the ON-state of the switch means for modifying the control signal so as to start switching the switch means to the OFF-state during a lapse of time substantially less than the time required for the switch means to reach the OFF-state and for restoring the control signal to a value corresponding to the ON-state at or before the end of the lapse of time, and comparator means responsive to variation of voltage at the output terminals during the lapse of time. The duration of the variation of voltage during the open-load detection is too short and its magnitude too small for the variation of load current to be perceptible, notably in the case where the load is a lamp.

A power cable breaking detection method for a vehicle includes detecting currents of respective phases supplied to a three-phase motor from an inverter through at least a power cable, and a driving speed of the motor, determining whether the respective currents and the driving speed of the motor satisfy power cable breaking detection conditions, determining whether various conditions are satisfied with respect to a cable breaking sensing reference value of a current command performing cable breaking timer counting when the conditions are satisfied, and determining whether a predetermined period has elapsed such that a cable is considered broken when the predetermined period has elapsed.

The electrical equipment of the present invention is operated such that the ON operating member for the primary power supply supplying circuit is manually operated, the switch device S is turned ON and when a supplying of electrical power for the primary power supply supplying circuit is shut off, the circuit for the control system is operated and upon performing a predetermined security processing, the driving source is driven, the OFF operating member is automatically operated, the switch device S is automatically turned OFF and supplying of an electrical power to the primary power supply supplying circuit is automatically shut off, so that it is possible to perform an appropriate processing before shutting off the primary power supply supplying circuit and thus it is also possible to provide electrical equipment showing a high safety characteristic.

A device for connecting electric household appliances to an electric power main has an input line connectable to a terminal of an electric power main; and at least one output terminal. The connecting device also has a detection stage for detecting electric power drawn by the input line; and a selective coupling stage between the input line and the output terminal. The selective coupling stage is controlled by the detection stage to disconnect the output terminal from the input line when the detected electric power is below a predetermined threshold.

The invention relates to a control switch based on electric quantity measurement, comprising: electric quantity detector connected in series in equipment power supply branch to obtain equipment consumed electric quantity, electronic switch, and controller connected in series between the output end of the electric quantity detector and the control end of the electronic switch, which controls ON-OFF of the electronic switch according to the output of the electric quantity detector. And the invention also relates to an on-off control socket for the control switch, comprising: master control jack group, controlled jack group, and the control switch, where the equipment power supply branch is a master control jack branch, and the electronic switch is connected in series in the power supply branch of the controlled jack. And the circuit of the invention uses MCU as controller to digitize the detection results so as to make on-off control of the controlled socket group more accurate.

An electromotive drive for furniture, includes a power supply device, a manual control, and a control device. The power supply device has an disconnecting unit that can be controlled by means of a control line, the electrical control signal of said control line being able to be modified by a switching contact of the manual control such that, when the manual control has not been actuated, the power supply device can be switched into the “disconnection” operating state, said disconnecting unit being connected to a signal feedback arrangement of a control circuit of the power supply device and being integrated in a path of said signal feedback arrangement, or said disconnecting unit being set in, or placed on, an input path or an output path of the control device.

The invention relates to a photovoltaic module (1), comprising at least one solar cell (2) and a socket outlet (6), wherein the socket outlet (6) has the voltage outputs (4, 5) of the photovoltaic module (1). An evaluation and control unit (12), which detects a voltage (UA) and/or a current (IA) of the photovoltaic module (1), is arranged in or on the socket outlet (6) as an assembly (7). At least one switching element (16) is associated with the photovoltaic module (1), the switching element being actuable by the evaluation and control unit (12). The photovoltaic module (1) can be disconnected by means of the switching element (16). The evaluation and control unit (12) is designed in such a way that, on the basis of the detected voltage (UA) and/or the detected current (IA), a fault state can be detected and the switching element (16), on the basis of the detected fault state, can be actuated by the evaluation and control unit (12) in order to disconnect or short-circuit at least one of the voltage outputs (4, 5; 10, 11) of the photovoltaic module (1) or the assembly (7).

The invention relates to an automatic switch-on and switch-off device of an overhead line of an electric locomotive, by which the electric locomotive is automatically switched on when a pantograph touches a power supply overhead line and is automatically switched off when the pantograph leaves the power supply overhead line. The automatic switch-on and switch-off device comprises a voltage detection unit, a current detection unit, an overcurrent detection unit, a main switch, a control unit, a display alarm unit and a control power supply unit, wherein the current detection unit, the overcurrent detection unit and the main switch are connected in series in a direct current major loop; the voltage detection unit is connected between the direct current major loop and the ground; the output ends of an overvoltage detection unit, the current detection unit and the overcurrent detection unit are all connected with the input end of the control unit for program control; the output end of the control unit is connected with the main switch and the display alarm unit; and the control power supply unit provides power for the control unit. The invention ensures that the power supply of low overhead lines of drift laneways underground is safe and reliable and replaces a traditional power supply mode of manual power failure and power transmission.

A satellite payload power supply undervoltage protection control circuit includes an undervoltage detection circuit, an undervoltage action circuit, an input switch circuit, an on/off instruction circuit, and a power input switch MOS tube M1. The undervoltage detection circuit detects the bus voltage, the undervoltage action circuit outputs a pulse signal according to the detection situation of the undervoltage detection circuit, the switch machine command circuit performs logic or operation according to the shutdown command and the pulse signal output by the undervoltage action circuit, and controls the input The switch circuit and the power input switch the MOS transistor M1 to control whether the input of the load power supply is turned on. The circuit of the present invention uses few devices and is small in size, and at the same time combines with the power-on and power-off commands, which simplifies the difficulty of the interface. In the state of power-on or power-off, its own power consumption is very small and will not affect the primary bus voltage of the satellite. The circuit of the invention can meet the requirements of 28V, 42V and 100V satellite primary buses, and can be applied to satellites and spaceships such as deep space exploration and manned moon landing.

A method and apparatus for identifying an open phase of a circuit breaker on the basis of voltage. The method comprises: a protection apparatus measures three-phase voltages at two sides of a circuit breaker; respectively calculates a vector difference and an effective value of the voltages at two sides of the circuit breaker; when the phase voltages at two sides are both greater than 80% to 90% of a rated voltage, and the voltage vector difference at two sides of the one-phase or two-phase circuit breaker is greater than a set voltage, it is determined that the circuit breaker has an open phase; and actuates an alarming or tripping operation after a short time delay t.

The invention relates to a liquid crystal display, a backlight module and a drive method thereof. In order to provide open-circuit protection for the backlight module, a quasi open-circuit voltage is firstly generated according to the current flowing through a light source; if the backlight module receives a model signal corresponding to a high contrast mode, a compensating voltage is added into the quasi open-circuit voltage to generate a reference voltage; and if the reference voltage is higher than a feedback voltage at an input end of a feedback self light source, a drive voltage is output to the light source. By the invention, the false operation for an open-circuit protection circuit can be avoided.