Patent CA895280A successfully refreshed from Google Patents.
Patent EP0262957A2 successfully refreshed from Google Patents.
EP0262957A2
Expired / Lapsed
EP
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Dial impulse generating circuit in a radio telephone
Assignee: Toshiba Corp
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Filing: 1987-09-30
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Granted: —
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Expires: 2007-09-30
Abstract
Abstract A dial impulse generator in a radio telephone system in which a line relay (29,26) is not used to generate a dial impulse. Under a condition that contacts (26) of the line relay (29,26) are closed, a transistor (30) is driven to open and close a DC loop through a photocoupler (31) under control of a control circuit (12), thus sending the dial impulse to wire lines (3).
Inventors
- 👤 Yuji Umemoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:43
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/26; H04M1/30; H04M1/31; H04M1/312
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
96 words
A dial impulse generator in a radio telephone system having a master unit (1) connected to wire lines (3) and a radiophone (2) connected through radio lines to said master unit (1), characterized in that said master unit (1) comprising: first switching means (26) for establishing a DC loop of said wire lines: second switching means (30) for opening and closing said DC loop; and control means (12) for driving said second switching means (30) to send a dial impulse to said wire lines (3) under a condition that said first switching means (26) is closed.
Claim 2
Dependent Claim
96 words
A dial impulse generator in a radio telephone system having a master unit (1) connected to wire lines (3) and a radiophone (2) connected through radio lines to said master unit (1), characterized in that said master unit (1) comprising: first switching means (26) for establishing a DC loop of said wire lines: second switching means (30) for opening and closing said DC loop; and control means (12) for driving said second switching means (30) to send a dial impulse to said wire lines (3) under a condition that said first switching means (26) is closed.
Claim 3
Dependent Claim
32 words
A dial impulse generator as set forth in claim 1, wherein said first switching means (26) comprises contacts (26) of a line relay (29) that is turned ON in a speech mode.
Claim 4
Dependent Claim
19 words
A dial impulse generator as set forth in claim 1, wherein said second switching means (30) comprises a transistor.
Claim 5
Dependent Claim
32 words
A dial impulse generator as set forth in claim 1, wherein said master unit (1) further comprises isolation means (31) through which said control means (12) drives said second switching means (30).
Claim 6
Dependent Claim
18 words
A dial impulse generator as set forth in claim 4, wherein said isolation means (31) comprises a photocoupler.
References Cited (Backward Citations)
No citation records indexed.
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