Abstract: A protection circuit includes a power supply, a resistor-capacitor (RC) parallel circuit, an inverter, first and second electronic switches. The RC parallel circuit is connected to the power supply through a first resistor. An input terminal of the inverter is connected to the power supply through the first resistor. A first terminal of the first electronic switch is connected to an output terminal of the inverter. A second terminal of the first electronic switch is grounded. A third terminal of the first electronic switch is connected to the power supply through a second resistor. A first terminal of the second electronic switch is connected to the third terminal of the first electronic switch. A second terminal of the second electronic switch is connected to an electronic device. A third terminal of the second electronic switch is connected to an output power supply.

Abstract: A protection circuit includes a power supply, a resistor-capacitor (RC) parallel circuit, an inverter, first and second electronic switches. The RC parallel circuit is connected to the power supply through a first resistor. An input terminal of the inverter is connected to the power supply through the first resistor. A first terminal of the first electronic switch is connected to an output terminal of the inverter. A second terminal of the first electronic switch is grounded. A third terminal of the first electronic switch is connected to the power supply through a second resistor. A first terminal of the second electronic switch is connected to the third terminal of the first electronic switch. A second terminal of the second electronic switch is connected to an electronic device. A third terminal of the second electronic switch is connected to an output power supply.

Abstract: An all-in-one computer includes a hard disk drive (HDD), a main body, a cover, and a fasten member. The main body defines a receiving space to receive the HDD, and a fasten hole. The receiving space is bounded by a number of walls. A first raised edge protrudes from the number of walls in the receiving space. The cover includes a board, a first hook, and a mounting piece defining a through hole. The board includes opposite first and second ends. The first hook extends from the first end. The mounting piece extends from the second end. When the cover is mounted to the main body, the first hook snappingly hooks an inner side of the first raised edge, the board is stopped by the first raised edge, and the fasten member can extend through the through hole and engage in the fasten hole.

Abstract: A computer motherboard includes a number of peripheral device interfaces, first and second voltage output terminals, and a number of power supply circuits corresponding to the S peripheral device interfaces. Each peripheral device interface includes a first power pin and a second power pin. Each power supply circuit includes a delay circuit, and first to third electronic switches. The delay circuit controls the first electronic switch to be turned on after a delay time. The delay times of the power supply circuits are different. The second and third electronic switches are turned on in response to the first electronic switch being turned on. The first voltage output terminal is connected to the first power pin through the second electronic switch. The second voltage output terminal is connected to the second power pin through the third electronic switch.

Abstract: A computer motherboard includes a number of peripheral device interfaces, first and second voltage output terminals, and a number of power supply circuits corresponding to the S peripheral device interfaces. Each peripheral device interface includes a first power pin and a second power pin. Each power supply circuit includes a delay circuit, and first to third electronic switches. The delay circuit controls the first electronic switch to be turned on after a delay time. The delay times of the power supply circuits are different. The second and third electronic switches are turned on in response to the first electronic switch being turned on. The first voltage output terminal is connected to the first power pin through the second electronic switch. The second voltage output terminal is connected to the second power pin through the third electronic switch.

Abstract: An all-in-one electrical device includes a front enclosure module, a rear enclosure module, a touch screen, and a middle module. The front enclosure module includes a frame. An opening is defined in the frame. A number of restricting members extend backwards from the frame. The rear enclosure module includes a cover detachably fixed to the frame. The touch screen is received in the frame and exposed through the opening. A forward freedom of motion (FOM) of the touch screen is restricted by the frame. Leftward, rightward, upward and downward FOMs of the touch screen are restricted by the number of restricting members. The middle module is detachably fixed to the frame and received between the frame and the cover. The middle module restricts a backward FOM of the touch screen.

Abstract: An all-in-one computer includes a hard disk drive (HDD), a main body, a cover, and a fasten member. The main body defines a receiving space to receive the HDD, and a fasten hole. The receiving space is bounded by a number of walls. A first raised edge protrudes from the number of walls in the receiving space. The cover includes a board, a first hook, and a mounting piece defining a through hole. The board includes opposite first and second ends. The first hook extends from the first end. The mounting piece extends from the second end. When the cover is mounted to the main body, the first hook snappingly hooks an inner side of the first raised edge, the board is stopped by the first raised edge, and the fasten member can extend through the through hole and engage in the fasten hole.

Abstract: An all-in-one computer includes a front enclosure and a rear enclosure fixed together. The front enclosure includes a rear piece opposite to the front enclosure, and two side pieces extending forwards from left and right ends, respectively. The rear piece defines an air outlet including a number of first holes each having a width or diameter between 1 mm and 2 mm. Each side piece defines an air intake including a number of vertically spaced elongated second holes. The front enclosure and the rear enclosure cooperatively bound an airtight space except communicating with outside via the air intakes and the air outlet. Each second hole is slanted lengthwise down towards the front enclosure with a first slanting angle of not less than 15 degrees. A bottom wall of each second hole is slanted down outwards with a second slanting angle of not less than 30 degrees.

Abstract: A voltage comparator circuit includes a voltage input terminal, a first resistor, a second resistor, a first transistor, a second transistor, and a voltage output terminal connected to the collector of the second transistor. The voltage input terminal is connected to ground via the first and second resistors in turn. A node between the first and second resistors is connected to the base of the first transistor. The emitter of the first transistor is grounded. The collector of the first transistor is connected to a direct current (DC) power supply and the base of the second transistor. The emitter of the second transistor is connected to the DC power supply.

Abstract: A circuit (11) utilizing a serial advanced technology attachment (ATA) interface for transmitting connectivity signals from the serial ATA interface to a controller (10) in order for the controller to determine a status of connectivity of a hard drive disk (HDD) (21) to the serial ATA interface. The circuit includes an input end (A) connecting to a ground end of the serial ATA interface, and electronically connecting to a high voltage source; a positive-negative-positive (PNP) tripolar transistor (Q1), a first negative-positive-negative (NPN) tripolar transistor (Q2), a second NPN tripolar transistor (Q3), and an output end connecting a collector of the second NPN tripolar transistor with the controller for outputting voltage signals to the controller. The controller is a programmable microprocessor for determining whether or not the HDD is connected to the serial ATA interface, based on the voltage signals input to the controller.

Abstract: A circuit (11) utilizing a serial advanced technology attachment (ATA) interface for transmitting connectivity signals from the serial ATA interface to a controller (10) in order for the controller to determine a status of connectivity of a hard drive disk (HDD) (21) to the serial ATA interface. The circuit includes an input end (A) connecting to a ground end of the serial ATA interface, and electronically connecting to a high voltage source; a positive-negative-positive (PNP) tripolar transistor (Q1), a first negative-positive-negative (NPN) tripolar transistor (Q2), a second NPN tripolar transistor (Q3), and an output end connecting a collector of the second NPN tripolar transistor with the controller for outputting voltage signals to the controller. The controller is a programmable microprocessor for determining whether or not the HDD is connected to the serial ATA interface, based on the voltage signals input to the controller.