IT1023541B - Protective cct for loudspeakers - has relay cct responding to overcurrent and DC voltage detector ccts - Google Patents
Protective cct for loudspeakers - has relay cct responding to overcurrent and DC voltage detector cctsInfo
- Publication number
- IT1023541B IT1023541B IT8340573A IT8340573A IT1023541B IT 1023541 B IT1023541 B IT 1023541B IT 8340573 A IT8340573 A IT 8340573A IT 8340573 A IT8340573 A IT 8340573A IT 1023541 B IT1023541 B IT 1023541B
- Authority
- IT
- Italy
- Prior art keywords
- relay
- cct
- circuit
- voltage detector
- responding
- Prior art date
Links
Landscapes
- Amplifiers (AREA)
- Protection Of Static Devices (AREA)
- Circuit For Audible Band Transducer (AREA)
Abstract
The transistor amplifier and loudspeaker protective circuit, for use with a sound system, includes a pair of relay contacts connected between a loudspeaker and a point in the emitter-resistors of the final stage transistors (Q6, Q7) of the transistor amplifier, and a relay circuit responding to the operation of an overcurrent detector circuit and a d.c. voltage detector circuit to open the relay contactts as required. The relay circuit includes a relay coil (4) and transistors (Q4, Q5), the operation of Q4 being controlled by a time constant circuit (C1, R10, R11, R12) and Q4 is further associated with a current limiting resistor, the coil being energised to close the relay contacts a given time after closure of a power switch. The voltage detector circuit detects fluctuations in the potential at the point by use of transistors (Q2, Q3, Q8).
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP47087585A JPS4945669A (en) | 1972-09-02 | 1972-09-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| IT1023541B true IT1023541B (en) | 1978-05-30 |
Family
ID=13919065
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IT8340573A IT1023541B (en) | 1972-09-02 | 1973-07-26 | Protective cct for loudspeakers - has relay cct responding to overcurrent and DC voltage detector ccts |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS4945669A (en) |
| IT (1) | IT1023541B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5941621Y2 (en) * | 1978-05-10 | 1984-12-01 | パイオニア株式会社 | Overload detection circuit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3856941A (en) * | 1972-05-23 | 1974-12-24 | Sobel J | Astringent gel, its preparation and use |
-
1972
- 1972-09-02 JP JP47087585A patent/JPS4945669A/ja active Pending
-
1973
- 1973-07-26 IT IT8340573A patent/IT1023541B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| JPS4945669A (en) | 1974-05-01 |
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