Abstract: A coin sensor comprising a first inductive branch with a first inductor in series with a first resistor; a second inductive branch with a second inductor in series with a second resistor, wherein the first and second inductors are arranged facing each other on both sides of a passage channel of coins to be discriminated; at least one capacitive branch with a condenser and a resistor in series; an excitation circuit with a generator and at least one pair of switches, configured to alternately feed the first inductive branch and the second inductive branch with a pattern signal with spectral energy in two or more frequencies, such that the branch of the inductor excited at any given time is arranged in a bridge configuration with at least one capacitive branch; at least one differential amplifier configured to alternately measure the voltage between the exit nodes of the excited bridge.

Abstract: A coin sensor comprising a first inductive branch with a first inductor in series with a first resistor; a second inductive branch with a second inductor in series with a second resistor, wherein the first and second inductors are arranged facing each other on both sides of a passage channel of coins to be discriminated; at least one capacitive branch with a condenser and a resistor in series; an excitation circuit with a generator and at least one pair of switches, configured to alternately feed the first inductive branch and the second inductive branch with a pattern signal with spectral energy in two or more frequencies, such that the branch of the inductor excited at any given time is arranged in a bridge configuration with at least one capacitive branch; at least one differential amplifier configured to alternately measure the voltage between the exit nodes of the excited bridge.

Abstract: The energy of the sound radiation caused by the impact of the coin to be analyzed upon a hard surface is split into different frequency bands, the energy of every such band is obtained and the ratios between them are then worked out, obtaining parameters that are then compared against values representing valid coins. The device includes a bank of filters (6, 7 and 8), integrators (9, 10 and 11) connected to the outlet of the filters and capable of being activated from a microprocessor (17) and an analogue-digital converter to which the output of the various integrators is then connected through a multiplexer.

Abstract: Device for the successive display of pictures in recreational machines, the device of which consists of a structure or frame which serves as a support for a series of rollers consisting of two synchronised drag rollers, consecutive and having a fixed position (2 and 2) and at least one removable guide roller (4), the position of which can be adjusted. The device may also include at least one fixed-position guide roller (5).

Abstract: A process for characterization of magnetic materials for validating documents carrying marks which include magnetic materials is based on an analysis of signals supplied by an oscillator generating a low frequency signal supplying emitter windings and receiver windings that have different conformations. The receiver windings (A) and (B) are joined to an amplifier that has two outputs (S1) and (S2), output (S2) yielding, upon conformation, a signal (X) that is used as a time reference, and output (S1) yielding, after various transformations, two signals (Y) and (Z), each of which is entered into a microprocessor which, together with valid magnetic marker data, generate signals accepting or rejecting the document.

Abstract: Device for the successive exposure of images in amusement machines, made up of a structure (1) that supports two consecutive synchronized dragging rollers (3 and 4), at least two consecutive fixed position guiding rollers (5 and 6) and two non consecutive, removable, adjustable position guiding rollers (7 and 8), upon which rollers is mounted a flexible continuous strip (22), bearing images that pass in front of a viewing window, near which are fitted lighting means (23), including furthermore means (30, 31, 32, 35) used to control the position of the images.