Abstract: A slidable wind instrument brace has an adjusting ring, a first abutting block and a second abutting block. The first abutting block and the second abutting block are respectively mounted on two ends of the adjusting ring. The adjusting ring is rotated to drive the first abutting block and the second abutting block to move close to or away from each other. Therefore, a position of the brace is changeable and a wind instrument with the brace can produce different timbres.

Abstract: A test board for testing PCBs includes a plurality of signal input terminals, a plurality of signal output terminals connected to the signal input terminals respectively, a standby signal output terminal, and a plurality of switches. The standby signal output terminal is connected to the signal input terminals via the switches respectively.

Abstract: An exemplary multi-user login method for a computer numerical control (CNC) machine includes: initializing a program installed in the CNC machine, thereby displaying a user selection interface on a screen of the CNC machine; a user inputting a user name and password on the user selection interface; the program of the CNC machine determining whether or not the user is registered based on the user name and password entered; if the user is registered, an operating system of the CNC machine loading a driver program installed in a motion control card of the CNC machine, and the driver program reading the user's personal information stored in the motion control card; and accessing a user operation interface of the registered user.

Abstract: A monitoring and control apparatus for monitoring and controlling computer numerical control (CNC) machines. The monitoring and control apparatus includes a monitoring and control device, a movement control card, and a movement control daughter card. The movement control daughter card is connected between the movement control card and a movable portion of the CNC machine so the movement control card controls the movable portion of the CNC machine using the movement control daughter card. The movement control daughter card includes a plurality of movement signal interfaces, a microprocessor, and a wireless transmitter. The plurality of movement signal interfaces are connected to the CNC machine to receive a plurality of status signals from the CNC machine. The microprocessor is for storing the status signals. The wireless transmitter is for transmitting the status signals from the microprocessor to the monitoring and control device.

Abstract: A test board for testing PCBs includes a plurality of signal input terminals, a plurality of signal output terminals connected to the signal input terminals respectively, a standby signal output terminal, and a plurality of switches. The standby signal output terminal is connected to the signal input terminals via the switches respectively.