Method and circuit to start and operate high pressure discharge lamps
First Claim
1. A method for starting and operating a high pressure discharge lamp with a discharge vessel containing an ionizable filling and in which at least two electrodes are included, wherein at the electrodes, via power supply leads extended to the outside in a gas tight manner, a high-frequency starting voltage UHF and an operating voltage UB are produced, comprising the steps of:
- turning on the high-frequency starting voltage UHF at starting time t0 to ionize the filling and preheat the electrodes, andturning on the operating voltage UB at time t1 =t0 +Δ
tH, after an interval Δ
tH.
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Accused Products
Abstract
Start and operation of high pressure discharge lamps, in which a high-frequency starting voltage UHF and an operating voltage UB are furnished to the lamp electrodes includes the steps of: 1) turning on the high-frequency starting voltage UHF at a starting time t0 to ionize the lamp filling and preheat the electrodes; 2) turning on the operating voltage UB after a preheating interval ΔtH, that is, at time t1 =t0 +ΔtH ; and 3) turning off the starting voltage UHF at time t2 ≧t1, as a result of which the lamp is then operated solely by means of the operating voltage UB. As a result, the transfer phase for the development of the arc is shortened. Advantageously, the frequency of the starting voltage is selected such that the product of the frequency f of the starting voltage UHF and the spacing d between the electrodes meets the condition f·d≧50 kHz·cm. A circuit arrangement for carrying out this method includes an HF ignition device and an operating device, which are each connected to the electrodes of the lamp via a respective switch, and the two switches are actuated by means of timers.
12 Citations
21 Claims
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1. A method for starting and operating a high pressure discharge lamp with a discharge vessel containing an ionizable filling and in which at least two electrodes are included, wherein at the electrodes, via power supply leads extended to the outside in a gas tight manner, a high-frequency starting voltage UHF and an operating voltage UB are produced, comprising the steps of:
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turning on the high-frequency starting voltage UHF at starting time t0 to ionize the filling and preheat the electrodes, and turning on the operating voltage UB at time t1 =t0 +Δ
tH, after an interval Δ
tH. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An apparatus for starting and operating a high pressure discharge lamp (EL) with a discharge vessel containing an ionizable filling and in which at least two electrodes are included, comprising:
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an HF ignition device (Z), which is connected to a first switch (S1) and provides a high-frequency starting voltage; an operating device (V), which is connected to a second switch (S2) and provides an operating voltage, and wherein outputs of both the operating device and the HF ignition device (V;
Z) are connected to the electrodes of the discharge lamp (EL); anda timer (T) that controls both switches (S1, S2). - View Dependent Claims (17, 18, 19, 20, 21)
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Specification