US3733524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Degaussing circuit
Assignee: Singer Co
•
Filing: 1972-03-01
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Granted: 1973-05-15
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Expires: 1992-03-01
Abstract
Abstract A degaussing circuit having fast recovery time for use in television displays, particularly useful where the display is frequently moved and requires frequent degaussing. By using a parallel combination of two diodes and two capacitors in series placed between the source and the degaussing coil a current which is initially at a maximum but decreases towards zero as the capacitors charge is provided. Additional means provide for quick discharge of the capacitors for immediate reuse of the circuit and for a reduction of any leakage current.
Inventors
- 👤 J Cooksey
- 👤 J Fazio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:47
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/16; H04N9/29; H01; H01F; H01F13/00; H01F13/006
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A circuit for placement between an alternating current source and a degaussing coil to control the current supplied to the coil comprising: a. a first diode with its anode connected to one side of the source; b. a first capacitor and first resistor in parallel connected on one side to the cathode of said first diode; c. a second diode with its cathode connected to the source; d. a second capacitor and second resistor in parallel connected on one side to the anode of said second diode and on the other side to the other side of said first capacitor and first resistor and to one side the degaussing coil; and e. a connection from the other side of said source to the other side of said degaussing coil.
Claim 2
Dependent Claim
129 words
A circuit for placement between an alternating current source and a degaussing coil to control the current supplied to the coil comprising: a. a first diode with its anode connected to one side of the source; b. a first capacitor and first resistor in parallel connected on one side to the cathode of said first diode; c. a second diode with its cathode connected to the source; d. a second capacitor and second resistor in parallel connected on one side to the anode of said second diode and on the other side to the other side of said first capacitor and first resistor and to one side the degaussing coil; and e. a connection from the other side of said source to the other side of said degaussing coil.
Claim 3
Dependent Claim
16 words
The invention according to claim 1 and further including a resistor in series with said coil.
Claim 4
Dependent Claim
20 words
The invention according to claim 1 and further including a switch between said source and said first and second diodes.
Claim 5
Dependent Claim
19 words
The invention according to claim 1 wherein said degaussing coil is used to degauss a color television picture tube.
Claim 6
Dependent Claim
32 words
The invention according to claim 1 and further including means to substantially reduce the current available to said circuit at a predetermined time after current is first made available from said source.
Claim 7
Dependent Claim
43 words
The invention according to claim 4 wherein said means comprise: a. a triac placed in the path between said source and said coil; and b. means to turn on said triac, and at a predetermined time after turn-on to turn off said triac.
Claim 8
Dependent Claim
60 words
The invention according to claim 5 wherein said means to turn said triac on and off comprise: a. a transistor having its output connected to control said triac such that when said transistor is on said triac will be on; and b. means to turn said transistor on and to turn said transistor off at a predetermined time after turn-on.
Claim 9
Dependent Claim
70 words
The invention according to claim 6 wherein said means to turn said transistor on and off comprise; a. means to provide a voltage to said transistor; b. biasing means in the base circuit of said transistor including a third capacitor arranged so that on application of a voltage said transistor will turn on and, after a predetermined time controlled by the time constant of said biasing means, will turn off.
Claim 10
Dependent Claim
30 words
The invention according to claim 7 wherein said means to apply voltage is a first two-position switch connecting said transistor to a DC voltage source when in a first position.
Claim 11
Dependent Claim
86 words
The invention according to claim 8 and further including a second switch, paralleled with said first switch, connected on one side to the one side of said first capacitor and resistor and on the other side to one side of a third resistor, said third resistor connected on the other side to said one side of said second capacitor and resistor, said second switch being open when said first switch is in said first position and closed when said first switch is in a second position.
Claim 12
Dependent Claim
48 words
The invention according to claim 9 wherein said circuit is used in a color television display and said DC voltage source is on when said display is on whereby turning said display on with said first switch in said first position will cause said display to be degaussed.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |