US3870831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone hold circuit
Assignee: Individual
•
Filing: 1973-06-27
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Granted: 1975-03-11
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Expires: 1993-06-27
Abstract
Abstract A telephone hold circuit for permitting either an incoming or an outgoing call to be held indefinitely, or as long as the party on the other end does not hang up. The circuit employs a silicon controlled switch for latching the circuit in the ''''hold'''' condition. The circuit also employs a light emitting diode to provide visual indication when the circuit is in the ''''hold'''' condition.
Inventors
- 👤 William I Mccarley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:55
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/428; H04M3/4283
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
271 words
A telephone hold circuit for connection to a telephone line having a positive conductor and a negative conductor: a load including a first and second terminal; electronic switch means having an input electrode, an output electrode, and a control electrode; visual indicator means connected in series between the first terminal of said load and the input electrode of said electronic switch means for providing visual indication when current passes therethrough; means connecting the second terminal of said load to the positive conductor of the telephone line; means connecting the output electrode of said electronic switch means to the negative conductor of the telephone line; first capacitor means connected across said load; second capacitor means including two leads; second switch means including two terminals having current passing and current blocking states; means connecting said second switch means and said second capacitor means in series across said visual indicator means and said electronic switch means with one terminal of said second switch means being connected to the junction between said load and said visual indicator means, and with a first lead of said second capacitor means being connected to the output electrode of said electronic switch means; actuation means coupled to said second switch means for establishing said second switch means in the current passing state whereby said second capacitor means may be charged; and resistance means coupling the second lead of said second capacitor means to the control electrode of said electronic switch means to render said electronic switch means conductive when said second capacitor means is charged to permit a current to pass through said load and said visual indicator means.
Claim 2
Dependent Claim
271 words
A telephone hold circuit for connection to a telephone line having a positive conductor and a negative conductor: a load including a first and second terminal; electronic switch means having an input electrode, an output electrode, and a control electrode; visual indicator means connected in series between the first terminal of said load and the input electrode of said electronic switch means for providing visual indication when current passes therethrough; means connecting the second terminal of said load to the positive conductor of the telephone line; means connecting the output electrode of said electronic switch means to the negative conductor of the telephone line; first capacitor means connected across said load; second capacitor means including two leads; second switch means including two terminals having current passing and current blocking states; means connecting said second switch means and said second capacitor means in series across said visual indicator means and said electronic switch means with one terminal of said second switch means being connected to the junction between said load and said visual indicator means, and with a first lead of said second capacitor means being connected to the output electrode of said electronic switch means; actuation means coupled to said second switch means for establishing said second switch means in the current passing state whereby said second capacitor means may be charged; and resistance means coupling the second lead of said second capacitor means to the control electrode of said electronic switch means to render said electronic switch means conductive when said second capacitor means is charged to permit a current to pass through said load and said visual indicator means.
Claim 3
Dependent Claim
271 words
A telephone hold circuit for connection to a telephone line having a positive conductor and a negative conductor: a load including a first and second terminal; electronic switch means having an input electrode, an output electrode, and a control electrode; visual indicator means connected in series between the first terminal of said load and the input electrode of said electronic switch means for providing visual indication when current passes therethrough; means connecting the second terminal of said load to the positive conductor of the telephone line; means connecting the output electrode of said electronic switch means to the negative conductor of the telephone line; first capacitor means connected across said load; second capacitor means including two leads; second switch means including two terminals having current passing and current blocking states; means connecting said second switch means and said second capacitor means in series across said visual indicator means and said electronic switch means with one terminal of said second switch means being connected to the junction between said load and said visual indicator means, and with a first lead of said second capacitor means being connected to the output electrode of said electronic switch means; actuation means coupled to said second switch means for establishing said second switch means in the current passing state whereby said second capacitor means may be charged; and resistance means coupling the second lead of said second capacitor means to the control electrode of said electronic switch means to render said electronic switch means conductive when said second capacitor means is charged to permit a current to pass through said load and said visual indicator means.
Claim 4
Dependent Claim
271 words
A telephone hold circuit for connection to a telephone line having a positive conductor and a negative conductor: a load including a first and second terminal; electronic switch means having an input electrode, an output electrode, and a control electrode; visual indicator means connected in series between the first terminal of said load and the input electrode of said electronic switch means for providing visual indication when current passes therethrough; means connecting the second terminal of said load to the positive conductor of the telephone line; means connecting the output electrode of said electronic switch means to the negative conductor of the telephone line; first capacitor means connected across said load; second capacitor means including two leads; second switch means including two terminals having current passing and current blocking states; means connecting said second switch means and said second capacitor means in series across said visual indicator means and said electronic switch means with one terminal of said second switch means being connected to the junction between said load and said visual indicator means, and with a first lead of said second capacitor means being connected to the output electrode of said electronic switch means; actuation means coupled to said second switch means for establishing said second switch means in the current passing state whereby said second capacitor means may be charged; and resistance means coupling the second lead of said second capacitor means to the control electrode of said electronic switch means to render said electronic switch means conductive when said second capacitor means is charged to permit a current to pass through said load and said visual indicator means.
Claim 5
Dependent Claim
33 words
The electronic switching circuit as defined in claim 1 wherein said electronic switch means is characterized further to include: a controlled rectifier having an input electrode, an output electrode and a control electrode.
Claim 6
Dependent Claim
52 words
The telephone hold circuit as defined in claim 1 wherein said electronic switch means is characterized further to include: a silicon controlled switch having the anode thereof connected to the input electrode, having the cathode thereof connected to the output electrode, and having the cathode gate thereof connected to the control electrode.
References Cited (Backward Citations)
US3742151A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |