DE215874C

DE215874C -

Info

Publication number: DE215874C
Application number: DENDAT215874D
Authority: DE

Description

Patent-A ν Spruch:Patent-A ν saying:

Vorrichtung zum Stimmen von Klavieren und ähnlichen Saiteninstrumenten mit Hilfe eines der zu stimmenden Saite (h) gegenüber angeordneten Mikrophons, dadurch gekennzeichnet, daß das Mikrophon (c) in den primären Stromkreis eines geeigneten Transformators (a) eingeschaltet ist, während in den sekundären Stromkreis eine Oszillographenröhre (d) mit einer durch Versuche ermittelten, den betreffenden Tönen entsprechende Skala (e) eingefügt ist, wobei durch die Länge des darin auftretenden Glimmlichtes die Höhe des Tones an der Skala ersichtlich ist.Device for tuning pianos and similar stringed instruments with the aid of a microphone arranged opposite the string (h) to be tuned, characterized in that the microphone (c) is connected to the primary circuit of a suitable transformer (a) , while a Oscillograph tube (d) with a scale (e) determined by experiments and corresponding to the relevant tones is inserted, the height of the tone on the scale being evident from the length of the glowing light occurring therein.

Hierzu 1 Blatt Zeichnungen.1 sheet of drawings.

12. Auflage, ausgegeben am 30. November igog.l12th edition, issued on November 30th igog.l

Claims

IMPERIAL

PATENT OFFICE.

The invention relates to a device for tuning pianos and the like String instruments, in which in a known manner the sound vibrations by means of a microphone can be transmitted to an electrical circuit. The innovation is there in the use of an oscilloscope tube to visualize the vibrations.

It is illustrated schematically in the drawing. The microphone c is arranged in the primary circuit I of a suitable transformer α opposite the string b to be tuned, while in the secondary circuit II an oscilloscope tube d , known per se, serving to monitor current, is switched on. This bears a scale e determined through experiments, on which the notes present on the piano are plotted according to the current fluctuation corresponding to the respective tone at a certain distance from the electrode, which is at a certain length that is proportional to the current strength of the cathode in the glow light occurring on the oscilloscope tube corresponds.

The regular successive air compressions and dilutions caused by the vibrations of the string. a periodic increase and decrease of the primary current passing through the microphone c , whereby the secondary current, the strength of which is proportional to the number of these oscillations, in the oscilloscope tube d provided with the scale e a glowing light from a. length corresponding to the strength of the current, which is a visible measure of the tension of the string in question, completely independent of hearing.