Abstract: The conversion of a first AC signal into a second AC signal (32) is performed from a first AC signal, from data and from measurement values obtained during conversion. During conversion, switches obtained during conversion. During conversion, Switches are activated with the aid of a computer, which, on the basis of data and measurement values, calculates the necessary frequency and amplitude of the second AC signal (32) at time intervals (A). Control sequences (Q1, Q2, Q3, etc. . . ) are applied to the switches, the latter controlling said sequences during the above-mentioned time intervals (A), in order to produce the second AC signal (32). An output signal of any desired frequency and amplitude shape can thus be obtained, and can also be modified during operation of the transformer.

Abstract: The invention relates to a combination of an apparatus for the transfer of fungible goods or services, for example, cashless payment for merchandise or services, with a transfer device having marked thereon a plurality of cancellable value units in the form of at least first and second types of optical markings different from one another, and arranged in a predetermined cyclical sequence on at least one track of the transfer device, without the occurrence of any gaps, but with a transition region formed between adjacent markings. The apparatus includes a reading device, inclusive of a light source, and at least first and second light sensors associated with the first and second types of optical markings, respectively. The reading device is arranged for reading and generating signals from the markings, and from the transition regions, and an activatable erasing device erases the markings in dependence of the number of value units to be cancelled.

Abstract: In a method and apparatus of identifying a document with the aid of at least two different types of optically readable markings disposed on the document, and of at least two light sensors, each individual marking modifying light impinging thereon in a characteristic manner, and wherein each light sensor is associated with a respective marking, and senses the light modified by the associated marking, the steps include placing the markings in a predetermined cyclical sequence on at least one track of the document, so as to avoid the creation of any optically readable gap, thereafter erasing at least selected portions of the markings, while maintaining in selected groups of two adjacent markings at least a portion of one of the markings in dependence of coded information to be recorded on the document, obtaining a timing signal from the light sensors in dependence of the light modified by the markings, with the aid of the timing signal, serially reading out the coded information from the marking portions remaini

Abstract: Apparatus for storing and reading data in association with a card which has a timing track comprising at least three different kinds of optically-readable timing markings arranged in the timing track in a cyclic sequence, and a data track, the apparatus including three optical timing sensors respectively responsive to the three different kinds of timing markings, and a reading direction detector controlled by the timing sensors.