US4001633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device provided with a gas and/or vapor discharge tube
Assignee: US Philips Corp
•
Filing: 1975-04-28
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Granted: 1977-01-04
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Expires: 1995-04-28
Abstract
Abstract A discharge lamp has an electrically conducting transparent layer and a temperature control which responds to variations of the lamp current to control lamp temperature. A control member causes an auxiliary current to flow intermittently through the said layer. The temperature control is adjusted so that in the operational condition the lamp will always be operating in a voltage-current range having a positive nature. As a result, the lamp does not require an electric stabilizing ballast.
Inventors
- 👤 Hendricus Franciscus Joannes Jacobus van Tongeren
- 👤 Jan Evert VAN DER Werf
- 👤 Jean Johan Heuvelmans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:23
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
110 words
Discharge tube apparatus which comprises: first and second input terminals, a discharge tube having first and second electrodes, an electric heating element which extends along at least part of the length of the tube and means for controlling said electric heating element to maintain said tube at a temperature such that said tube is substantially maintained in the positive parts of the voltage-current characteristics of said tube, said means for controlling being provided with a control member which in the operating condition of the discharge tube mainly responds to variations of the effective value of the current flowing through the tube to control the current flowing through the heating element.
Claim 2
Dependent Claim
110 words
Discharge tube apparatus which comprises: first and second input terminals, a discharge tube having first and second electrodes, an electric heating element which extends along at least part of the length of the tube and means for controlling said electric heating element to maintain said tube at a temperature such that said tube is substantially maintained in the positive parts of the voltage-current characteristics of said tube, said means for controlling being provided with a control member which in the operating condition of the discharge tube mainly responds to variations of the effective value of the current flowing through the tube to control the current flowing through the heating element.
Claim 3
Dependent Claim
62 words
Apparatus as claimed in claim 1, characterized in that the control member of said means for controlling is coupled to a switch which is connected in series with the heating element, said switch in one mode preventing current flow through the heating element and in another mode connecting the heating element in parallel with a circuit branch which includes the discharge tube.
Claim 4
Dependent Claim
28 words
Apparatus as claimed in claim 1 wherein the control member is a reed relay having an energizing winding connected to said circuit branch which includes the discharge tube.
Claim 5
Dependent Claim
25 words
Apparatus as claimed in claim 2 wherein said switch is a transistor having a base which is connected to a contact of the reed relay.
Claim 6
Dependent Claim
18 words
Apparatus as claimed in claim 1 wherein the heating element is a wire wound around the discharge tube.
Claim 7
Dependent Claim
28 words
Apparatus as claimed in claim 1 wherein the heating element is in the form of a layer which is transparent to visible radiation and envelops the discharge tube.
Claim 8
Dependent Claim
29 words
Apparatus as claimed in claim 6 in which the discharge tube is a low pressure sodium vapor discharge tube wherein the layer which transmits visible radiation reflects infrared radiation.
Claim 9
Dependent Claim
27 words
Apparatus as claimed in claim 1 for cooperation with an associated alternating-voltage supply, said apparatus including a bridge rectifier connected to supply direct current to the lamp.
Claim 10
Dependent Claim
21 words
The apparatus as described in claim 1 wherein said means for controlling intermittently stops and starts current flow through said heater.
References Cited (Backward Citations)
NL6511266A
Cited
US3961222A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |