Abstract:
A power distribution system capable of automatic fault detection includes a lateral, a switch unit and a feeder terminal unit. The switch unit includes a circuit breaker coupled for transmitting electrical power to the lateral when making electrical connection, and a protection relay to provide a control signal that causes the circuit breaker to break electrical connection upon determining that the magnitude of a current provided by the circuit breaker is greater than a threshold current value. The feeder terminal unit detects whether or not the protection relay generates the control signal, so as to determine whether or not a fault has occurred in the lateral.
Abstract:
A method for estimating an position of wireless network equipment, including setting a wireless network transmission parameter, wherein the wireless network transmission parameter includes a transmitting power, a carrier frequency and a spreading factor index, which are used for performing an initial operation setting of wireless network; according to the wireless network transmission parameter, providing a path loss index and a reference distance for simulating an actual wireless network environment; selecting a noise power to simulate a signal state of a transmission path; and according to a field domain, setting a received power threshold to calculate a predetermined transmission distance of wireless network equipment erection. By means of the above method, a better setting position of a better wireless terminal equipment can be calculated more efficiently, and a proper position of a node equipment can be determined by using a signal measurement or packetized transfer reception and loss conditions in the vicinity of an estimated distance from a base station.
Abstract:
A light emitting diode (LED) driving circuit suitable for driving an LED load is provided. The LED driving circuit includes an AC voltage source, a bridge rectifier, a plurality of diodes, inductors, transistors and capacitors. The diodes, inductors, transistors and capacitors are configured to form a buck-boost converter and a buck converter, where the buck-boost converter and the buck converter share the transistors as active switches. Designer can design the LED driving circuit with zero-voltage switching-on using the diode characteristic of the existing active switches by selecting suitable circuit parameters.
Abstract:
A power distribution system capable of automatic fault detection includes a lateral, a switch unit and a feeder terminal unit. The switch unit includes a circuit breaker coupled for transmitting electrical power to the lateral when making electrical connection, and a protection relay to provide a control signal that causes the circuit breaker to break electrical connection upon determining that the magnitude of a current provided by the circuit breaker is greater than a threshold current value. The feeder terminal unit detects whether or not the protection relay generates the control signal, so as to determine whether or not a fault has occurred in the lateral.
Abstract:
A power monitoring system includes a power monitoring device and a host. The power monitoring device includes: a plurality of meters, each generating an input detection signal that indicates an electric quantity inputted to a respective load; a detecting unit generating an output detection signal that indicates an electric quantity outputted to a transformer; a processing unit generating, based on the output detection signal and the input detection signals, a state indicator that indicates the presence or absence of energy theft; and a communication unit generating a communication signal that carries the state indicator. The host generates a warning output when the state indicator carried by the communication signal received thereby indicates the presence of energy theft.
Abstract:
An LED driving device includes a DC to DC converter module and a driving module. The DC to DC converter module includes a full-bridge switching circuit for converting a first DC electric power into an AC electric power, a rectifier circuit for converting the AC electric power into a second DC electric power, and a control circuit for modulating pulse phase of the second DC electric power and for controlling switching operation of the full-bridge switching circuit, such that the second DC electric power has a predetermined voltage value. The driving module is operable to receive the second DC electric power, to output a third DC electric power with a predetermined current value for driving an LED module, and to modulate pulse width of the third DC electric power.