Digitally driven combination coils for electrodynamic acoustic transducers
US4360707A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1980 |
| Grant date | Nov 23, 1982 |
| Priority date | — |
| Expiry date | Nov 24, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2209/041
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An electrodynamic acoustic transducer (54) having two voice coils (50, 52), the coils being addressed by amplified digital signals. The system (12, 60, 54) utilizes a preamplified analog input signal (10) which is supplied to a bifurcated network, one such signal being processed by an inverter (18). The analog signals (42, 44) are compared with triangular waves (38, 40) to effect switched signals (46, 48) that are pulse width modulated signals. The signals (46, 48) are then amplified through impedances (76, 78) and high speed, high current semiconductor switch means (80, 82) so that the amplified digital signals serve as driver means communicated to the separately addressable coilds (50, 52). There is a dynamic balance achieved by separate energization of the coils (50, 52) whereby the diaphragm (97) is positively located in both axial driving directions and is disposed in equilibrium positions by the energization and balancing of the respective coils (50, 52). As a result, the dynamic range, clarity, cleaness, and response time is substantially improved. An important aspect of this invention is the direct addressing of two distinct coils (50, 52) by amplified pulse trains which ar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.