Abstract: A variable resistance measuring loop having a compensational function for environmental factors is provided. The variable resistance measuring loop includes a central processing unit; a variable resistance VR connected between first and second terminals of the central processing unit, as well as a transistor Q and resistance R coupled to respective terminals of the central processing unit, and a capacitor C coupled with the transistor Q to a center contact of the variable resistance VR. During operation, the variable resistance measuring loop establishes at least one of two discharging loop modes wherein discharge of the capacitor C occurs through one of either a resistance portion RA or a resistance portion RB of the variable resistance VR.

Abstract: A method for forming a keyboard switching circuit without generating phantom phenomenon is disclosed. The method includes the steps of (1) forming a matrix of nodes with input/output terminals of the keyboard circuit; (2) selecting nodes from the matrix to define a reference diagonal line which divides the matrix into upper and lower portions; (3) selectively selecting nodes of the matrix in the upper and/or lower portions to define diagonal lines parallel to the reference line, the diagonal lines being located at different distance from the reference lines and the nodes of the diagonal lines forming no rectangle with each other; and (4) setting switches in the selected nodes. Since no rectangle can be formed among the switches, no reverse current may be caused by simultaneous actuation of three switches of a rectangle and thus effectively eliminating phantom phenomenon.

Abstract: A variable resistance measuring loop having compensation function for environmental factor is disclosed. The measuring loop comprises a central processing unit CPU connected by one end of the variable resistance to the PO.1 leg thereof, and the other end being connected to the PO.2 leg thereof, the center end thereof being connected to a drain of a charging switch transistor Q, the base of the transistor Q being connected in series with a resistance R to the PO.3 leg of the CPU, the emitter of the transistor Q being connected to VDD power source end, the drain being conductive with the PO.

Abstract: The multiple-channel wireless input unit is applied to a computer system that involves the use of wireless peripherals. Each different input device is respectively controlled by a CPU to transmit signals from its transmitter at a different channel, while its receptor controls a CPU that in turn controls a scanning device to scan the input signals at different channels. The signals are then transmitted to the computer through a USP port. The receptor receives signals at different times by scanning operation to achieve the purpose of simultaneous reception of two packets of signals in a time-divided and labor-divided fashion, and upgrade the operational efficiency of the wireless input unit.

Abstract: A method of remote start of wireless transmission USB for application on computer systems of wireless perimeters as a sensor, formed by R/C charging/discharging devices or WATCH DOG TIME OUT, that regularly supplies power to wake up the sensor receiver through a remote start and, with signals available, the wake-up function could be carried out directly and in case no, the unit would switch to power-conservation suspend mode, so that the USB suspend power could be conserved.

Abstract: This invention is a wireless USB keyboard which comprises a signal encoding device between the keyboard switch key assembly and an emitter RF module. Pressing a keyboard matrix data switch encodes the data as data code for transmission. The emitter RF module transmits the signal to the receiver end, and it is transmitted to a computer via a USB port after decoding. The wireless USB keyboard, which transmits signals to the receiver end after encoding, can effectively transmit key matrix data, which prevents the keyboard signal from interfering with other wireless peripheral devices.

Abstract: A method for forming a keyboard switching circuit without generating phantom phenomenon is disclosed. The method includes the steps of (1) forming a matrix of nodes with input/output terminals of the keyboard circuit; (2) selecting nodes from the matrix to define a reference diagonal line which divides the matrix into upper and lower portions; (3) selectively selecting nodes of the matrix in the upper and/or lower portions to define diagonal lines parallel to the reference line, the diagonal lines being located at different distance from the reference lines and the nodes of the diagonal lines forming no rectangle with each other; and (4) setting switches in the selected nodes. Since no rectangle can be formed among the switches, no reverse current may be caused by simultaneous actuation of three switches of a rectangle and thus effectively eliminating phantom phenomenon.

Abstract: An apparatus and method capable to automatically detect and determine a computer keyboard in operation with USB mode or PS/2 mode is described. In an external connector mode, the apparatus comprises a central processing unit (CPU) with a power port, a ground port, and a first and second USB and PS/2 shared ports to connect with a USB connector or a PS/2 connector and detect the first and second USB and PS/2 shared ports to determine the computer keyboard in operation with USB mode or PS/2 mode. In a Y-cable mode, the apparatus comprises a CPU connected with a USB connector and a PS/2 connectors, and a mode detection circuit respectively connected to the power terminals of the USB connector and the PS/2 connector and outputting a first or second mode signal to the mode detection port on the CPU so as to determine the computer keyboard in operation with USB mode or PS/2 mode.

Abstract: A computer pointing device includes a casing having a top on which a button rotatably support by a ball joint. The button has a plurality of pins corresponding to a plurality of openings formed on the top of the casing. A rubber pad is disposed within the casing, having a plurality of raised projections respectively received within the openings, each having a hollow configuration to receive and retain therein a conductor. The projections selectively collapse when the button is depressed to have at least one of the pins engaging the corresponding projections via the openings so as to move the conductors thereof in a downward direction. A circuit board is disposed under the rubber pad, having conductive ribs formed thereon to be selectively engageable by each of the conductors when the projections collapses to cause the downward movement of the conductors.

Abstract: A transmission angle adjusting device includes a first transmission device and a second transmission device disposed on the computer and the keyboard respectively. Each of the first and the second transmission devices has an infrared transmitter, an infrared receiver and a transmission angle/direction adjusting device arranged between the transmitter and the computer (or the keyboard) or disposed between the receiver and the keyboard (or the computer). Since the transmission angle/direction adjusting device can adjust the transmission angle of the infrared transmitter, transmission signals from adjacently arranged transmission devices can be separated from each other in order to prevent interference.