Abstract: A wide band antenna includes a radiation element, a ground surface, a dielectric element, a connector; a first microstrip feeder and a second microstrip feeder. The radiation element is a rectangle shaped and includes a first side and a second side. The lengths of the first side and the second side are not equal. The dielectric element is positioned between the radiation element and the ground surface. One end of the first microstrip feeder is connected to the first side of the radiation element. One end of the second microstrip feeder is connected to the second side of the radiation element, the other ends of the first and second microstrip feeder are connected to the connector.

Abstract: A printed circuit board layout system includes an input unit, an executing unit, a layout unit and a labeling unit. The input unit configured to respond to user operation to generate operation instructions. The operation instructions include execution, layout, and label instructions. The executing unit displays the PCB layout diagram file based on a circuit schematic diagram in response to execution instructions. The layout unit designs the first routes of the PCB layout diagram. The labeling unit labels at least one of the first routes.

Abstract: A wide band antenna includes a radiation element, a ground surface, a dielectric element, a connector; a first microstrip feeder and a second microstrip feeder. The radiation element is a rectangle shaped and includes a first side and a second side. The lengths of the first side and the second side are not equal. The dielectric element is positioned between the radiation element and the ground surface. One end of the first microstrip feeder is connected to the first side of the radiation element. One end of the second microstrip feeder is connected to the second side of the radiation element, the other ends of the first and second microstrip feeder are connected to the connector.

Abstract: A dual-band antenna includes a RF connector, a radiation element, and a ground surface. The RF connector is connected to a RF receiver. The radiation element includes a first radiation element and a second radiation element. The first radiation element and the second radiation element are both connected to the RF connector. The RF connector is connected to the ground surface.

Abstract: A rotatable electric plug has a bottom case, a rotatable brace, a plug head, a limit cover and a top cover. The rotatable brace is rotatably mounted in the bottom case and has a top surface and two connectors being mounted on the top surface of the rotatable brace. The plug head is detachably mounted on the bottom case and is connected with the rotatable brace. Two pins of the plug head is electronically connected to the connectors respectively. The limit cover is mounted in the bottom case to position the rotatable brace. The top cover is mounted on the bottom case to hold the rotatable brace and the limit cover inside the bottom case.

Abstract: A charging protection circuit with an overcurrent protector circuit takes input from a power supply, and provides output power to a power storage device, such as a battery. A fuse is connected between an input and an output of the charging protection circuit to protect the power storage device from a current spike, or overcurrent, that would damage the power storage device. When the overcurrent is above a threshold of the fuse, the fuse melts, effectively creating an open circuit and blocking the overcurrent from reaching the power storage device. To speed up the fuse meltdown, the overcurrent protector circuit is connected to the output of the fuse, and draws an extra current through the fuse when the overcurrent is detected.