Musical door chime preferably also combined with a clock for annunciating the time
US4326276A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1979 |
| Grant date | Apr 20, 1982 |
| Priority date | — |
| Expiry date | Dec 4, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H2230/351
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A musical door chime which includes a repertoire of musical tunes one of which is played when a door pushbutton, preferably the front door pushbutton, is actuated. The musical tune which is played may be selected by means of a keyboard connected to a microprocessor. Digitally encoded representations of the notes of each musical tune are stored in a memory. Each digitally encoded musical note is read from memory by the microprocessor and converted by the microprocessor into a squarewave having the frequency and the duration of the note. The microprocessor is connected to a note strike and decay circuit which is preferably connected in series with an active audio filter circuit for translating the squarewave into a sinusoidal output for energizing a loudspeaker so that relatively high quality audible tones are heard when the musical tune is played. Preferably, a two-note musical tune is played when a rear door pushbutton is actuated, and a fixed single musical note is played when a side door pushbutton is actuated. The musical door chime is preferably also combined with a visual display driven by the microprocessor for indicating the time of day. The time is preferably annunciated ev…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.