Abstract: A USB-based wireless transmitting/receiving system includes a transmitting portion connected to at least one USB-based peripheral device for receiving a signal from the peripheral device and a receiving portion connected to a computer host and coupled to the transmitting portion in a wireless fashion for receiving and applying the signal from the transmitting portion to the computer host whereby a wireless communication is established between the computer host and the USB-based peripheral device. Both the transmitting portion and the receiving portion include a central processing unit for processing signals received, a receiving unit for receiving signals, a transmitting unit for transmitting signals and a power supply system for powering the transmitting portion or the receiving portion. The power supply system includes a regulation circuit adapted to connect to an electric main.

Abstract: A charging system is incorporated in a computer communicable through a predetermined communication channel with a wireless peripheral device having a predetermined identification code. The charging system includes a charging device mounted to and in electrical connection with the computer. The charging device has a positive terminal, a negative terminal and a reset terminal. A rechargeable device is mounted in the wireless peripheral device. The rechargeable device includes a positive terminal, a negative terminal and a reset terminal corresponding to and engageable with the terminals of the charging device. The wireless peripheral device is selectively attached to the computer with the terminals engage each other to conduct an electrical current from the computer to the rechargeable device of the peripheral device and to reset/identify the communication channel and the identification code.

Abstract: A digital rotary switch signal reading circuit is adapted to read volume control signal from a volume control knob mounted on a multi-medium keyboard. The rotary switch has two signal terminals and one common terminal. The signal terminals are connected to two of input pins of a microprocessor of the keyboard and the common terminal is connected to one of the output pins of the microprocessor, the input pins and the output pins being interconnected with each other to form a key array. Thus, the signal from the rotary switch may be read by the computer in the same way as key actuation signal from the key array.

Abstract: A digital rotary switch signal reading circuit is adapted to read volume control signal from a volume control knob mounted on a multi-medium keyboard. The rotary switch has two signal terminals and one common terminal. The signal terminals are connected to two of input pins of a microprocessor of the keyboard and the common terminal is connected to one of the output pins of the microprocessor, the input pins and the output pins being interconnected with each other to form a key array. Thus, the signal from the rotary switch may be read by the computer in the same way as key actuation signal from the key array.

Abstract: A system for identifying electric device includes a charging/discharging circuit comprised of at least one electric capacitor and one additional electric element, such as an electric resistor or an electric inductance. The charging/discharging circuit is connected to at least one input/output port of a central processing unit and has a particular charging/discharging characteristics based on values of the capacitor and the resistor or the inductance. The particular charging/discharging characteristics provides an identification code of the device. The identification code may be used to identify a particular product in for example a communication link between a central processing unit of a host machine and a peripheral device or be used to identify a particular model of products manufactured in a manufacturing line whereby the same facility may be used to manufacture different models of products thereby effectively reducing the manufacturing costs.