Abstract: A method of synchronising the replay of audio data sent as data packets in a network of computers is described. The audio data passes from a source station to destination stations within earshot of one another, and each data packet sets out from the source station to respective destination stations at substantially the same time, taking a travel time to reach its destination station. The travel times are distributed over a range of times, and are difficult to predict. The method includes determining the average travel time (or minimum travel time) of a data packet, and providing a delay between the time a given packet is sent and its replay, the delay being adapted such that it corresponds to a predetermined time equal to the average travel time (or minimum travel time) plus a variable time. This results in the synchronisation of audio data replay, because the average travel time (or minimum travel time) is approximately the same for neighbouring destination stations, on average.

Abstract: Methods of controlling the brightness of a glow discharge which switches from a low brightness state to a high brightness state a given time after the start of an excitation pulse are described. In the first method, conventional pulse duration modulation produces a dimming ratio much greater than the ratio of duty factor variation. In the second method, a plurality of sets of pulses having different fixed durations but variable repetition rates are employed. In the third method, a plurality of sets of pulses having different relative durations have their pulse durations modulated in synchrony.