GB1165070A - Automatic Rhythm Player - Google Patents

Abstract

1,165,070. Automatic rhythm player; readonly stores. NIPPON COLUMBIA K.K. 21 July, 1967 [23 July, 1966 (2); 6 Aug., 1966; 2 Feb., 1967]. No. 33669/67. Headings G4A and G5J. In an automatic rhythm player, rectangular pulses of period # from an oscillator 1 are fed to a pulse developing circuit 2 comprising multivibrators F 1 , F 2 and F 3 . A unique combination of three outputs from the positive terminals a, b, c and negative terminals a, b, c is connected to each of the AND-gates G 1 -G 8 , which produce pulse outputs of duration # and period 8#, each phase shifted from adjacent ones by a degree corresponding to #. The pulse outputs are fed to a rhythm circuit 4 which comprises a matrix of conductors L 1 -L 8 and S 1 -S 4 , selectively connected at their crossing points by diodes 6, to produce rhythms which, via switches 7 1 -7 4 drive circuits M 1 -M 4 which produce percussive, e.g. drum or maraca, tones. These tones are amplified at AM and drive a speaker Sp. Alternative memory circuits.-In a modification of the memory circuit shown in Fig. 3, a matrix of photo-electric elements e.g. photo-cells or phototransistors is disposed on one side of a selectively apertured opaque base-plate 4<SP>1</SP>. Lights from sources L, on the other side of the plate, pass through the apertures to sensitize corresponding photo-electric elements to produce rhythm pulses, which via a photoelectric switching matrix C L11 -C L14 , CL 21 - C L24 and C L31 -C L34 drive the percussion sound sources M 1 1-M 4 <SP>1</SP>. In another embodiment (Figs. 4-5, not shown) a single photo-electric element corresponds to each row of apertures and eight light sources (L 11 -L 18 ) respectively connected to the outputs of the pulse developing circuit (2) and sequentially switched on and off thereby provide pulse trains corresponding to the apertures of the previous example, which pulse trains can be combined with a desired sound source. In a further modification (Figs. 6-7, not shown) a matrix of apertures is formed in a non-magnetic base-plate (4<SP>111</SP>) and magnetic pieces (X) of permalloy or ferrite, selectively inserted in the apertures, couple rows and columns of coils disposed on both sides of the plate. In a still further embodiment (Figs. 8-9, not shown) the coils are replaced by electrodes which are electromagnetically coupled by ferroelectric pieces (Y) of barium titanate inserted in the apertures. In each embodiment of the memory circuit, accented rhythms may be produced as by connecting resistors in series with the diodes, or by using apertures of different diameters, or by using magnetic or ferroelectric coupling pieces of different thicknesses.