2529results about "Emergency protection detection" patented technology

The current invention is an automatic AC power interruption system built into a portable apparatus or integrated into electrical systems and appliance control circuitry. Power is interrupted in potentially hazardous conditions, for example, when a T3 smoke detector alarm signal is detected. Alternatively, a portable device may be plugged into a power outlet having a GFCI breaker and, when a hazard alarm condition is detected, trip off power to the outlet. Signal-activated circuit interrupters (SACIs) may be integrated into appliance control circuitry and interrupt power to a problematic device when a hazard alarm condition is detected. In addition to fire prevention, other hazard alarm conditions may include alarms indicating toxic fumes, motor overload, natural gas, radon, or carbon monoxide. Interconnected networks of signal-activated circuit interrupters are also disclosed.

A powered panel moving system includes a motor, electronic drive circuitry, a mechanism, a coupler, and electronic function circuitry. The drive circuitry drives a rotor of the motor. The coupler couples rotational output of the rotor to the mechanism to drive the mechanism in order to move the panel. The function circuitry is integrated with the drive circuitry for providing additional functionality beyond driving the motor for panel movement. The drive circuitry includes a current sensor for determining rotor position based on motor current, a back emf sensor for determining rotor position based on back emf of the motor, and an impedance sensor for determining rotor position based on motor impedance. The function circuitry may include an analyzer to determine presence of an obstruction to the motion of the panel based on at least one of the rotor position, the motor current, and the back emf of the motor.

A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller. The switch circuit has a second terminal to provide either a third signal or a third circuit condition effective to control the starter, in response to sensing one of the second signal and the second circuit condition. All of the transformer, the input circuit, and the switch circuit are located in a single unitary package which is easily mounted and adjusted to a desired position.

An electronic filter for filtering the output signal of a current sensor of a circuit breaker is disclosed. The current sensor has an output signal characteristic similar to that of a Rogowski coil output signal characteristic that includes a third harmonic noise component in response to a switching primary current of the circuit breaker, and the circuit breaker has an electronic trip unit with an instantaneous pick-up setting responsive to the output signal of the current sensor. The electronic filter includes a first stage and a second stage. The first stage has a first transfer function that defines first characteristic poles and permits passage of the third harmonic noise component. The second stage has a second transfer function that defines second characteristic poles and filters the third harmonic noise component.

Provided is an apparatus and method for identifying a specific lost current transformer (CT) signal of number of CT signals provided by a corresponding number of CTs coupling a protective device to at least one protection zone. The method includes selectively providing pairs of first and second binary control signals corresponding to each of the CT signals in response to comparisons of RMS current changes of respective CT signals. A third binary control signal associated with a protection zone is provided in response to receipt of the pairs of first and second binary control signals. A first value for only one of the first binary control signals, a second value for all of the second binary control signals and the first value for the third binary control signal for a predetermined time indicates the loss of the CT signal corresponding to the first binary control signal having the first value.

Relay devices, systems and methods for obtaining an accurate representation of a current monitored with a Rogowski coil, without integration of the Rogowski coil output voltage signal in the time domain.

A current detector (60) samples a motor current (MCRT_A) from a controlling sensor and a motor current (MCRT_B) from a monitoring sensor, and holds respective motor current maximum values (MCRT_Amax, MCRT_Bmax) at each prescribed operation cycle. An abnormality determiner (62a) detects that the motor current maximum value (MCRT_Amax) is in GND short-circuiting range and that the current difference between the maximum values exceeds a prescribed threshold value at each of successive operation cycles, to thereby determine an abnormality of the controlling sensor. Then, the abnormality determiner (62a) generates a detect signal (DET) specifying the current sensor abnormality and outputs it to a relay driver (64) and an alarm (66). Relay driver (64) receives the detect signal (DET) and generates a signal (SE) to turn off a system relay. The alarm (66) generates a signal (AL) and outputs it to display means arranged outside a power supply apparatus.