Abstract: When a network is formed among vehicles with the use of inter-vehicle communication units, a network-forming-request-source vehicle sends its position serving as a reference position, its moving direction, and requested information to surrounding vehicles by the use of a free ID. Among the surrounding vehicles, vehicles which are to subscribe to the network receive the position, the moving direction, and the requested information, determine where the vehicles are positioned among positions specified in advance relative to the reference position, and respond at a timing corresponding to their positions by the use of free IDs. The network-forming-request-source vehicle receives the responses, stops receiving responses when the number of responded vehicles reaches an appropriate number of vehicles, and sends its genuine ID and a vehicle communication order.

Abstract: When a network is formed among vehicles with the use of inter-vehicle communication units, a network-forming-request-source vehicle sends its position serving as a reference position, its moving direction, and requested information to surrounding vehicles by the use of a free ID. Among the surrounding vehicles, vehicles which are to subscribe to the network receive the position, the moving direction, and the requested information, determine where the vehicles are positioned among positions specified in advance relative to the reference position, and respond at a timing corresponding to their positions by the use of free IDs. The network-forming-request-source vehicle receives the responses, stops receiving responses when the number of responded vehicles reaches an appropriate number of vehicles, and sends its genuine ID and a vehicle communication order.

Abstract: A digital analog converter which is especially suitable for use in converting a digital audio signal into an analog audio signal includes a unit pulse response signal generator for successively generating unit pulse response signals at a predetermined time interval, a digital data generator for generating digital data at the predetermined time interval, a multiplier for multiplying a unit pulse response signal generated at a certain time by a predetermined item of the digital data, and a mixer for producing an analog signal output by combining the unit pulse response signals that have been multiplied by the digital data.

Abstract: In a presettable graphic equalizer for use in a car stereo or the like, a display device capable of two-dimensional display is disposed, whereby a frequency characteristic presently given to audio signals can be immediately known from the display of the display device.

Abstract: An electronic volume for effecting a control of an impedance circuit in audio devices or the like includes a variable impedance circuit disposed in a signal transmission path and adapted to vary the impedance in accordance with an electronic control signal. A hold/through gate switchable between a hold state and a through state and adapted to permit, when taking the through state, the input signal to pass therethrough in synchronization with a clock signal of a predetermined period and, when taking the hold state, to hold and deliver the input signal as a control signal to the variable impedance circuit, is connected to a control circuit adapted to vary the input signal supplied to the hold/through gate at a predetermined rate at each time of receipt of the hold/through gate, and a rate changing means is provided for changing the rate of variation of the input signal coming through the hold/through gate.