Method and apparatus for actuating solenoids in a player piano
US5756910A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Dec 18, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H1/0066
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A method and apparatus for actuating solenoids in an electronic player piano where a Musical Instrument Digital Interface (MIDI) velocity value is translated to a solenoid driving signal, a counter is activated by the solenoid driving signal, and a solenoid is energized from the counter according to the solenoid driving signal. A central processing unit (CPU) reads the MIDI data from a digital data storage device, and selects the corresponding solenoid driving parameters from a look-up table stored in read only memory (ROM). The solenoid driving parameters are converted into a pulse width modulation (PWM) waveform by a driving circuit containing counters. The PWM signal is sent to the gate of a field effect transistor (FET) switch connected to the solenoid and the solenoid is energized by the FET according to the PWM signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.