| 摘要 |
A lighting system having a high intensity discharge lamp 100 mounted in an adaptor 150 which in turn connects replaceably to an electronic control circuit (8, figure 3). The control is arranged to sweep over a predetermined range of frequencies to start the lamp at a resonant frequency of a joint operating circuit (22, figure 3), the latter having a control reactance in the control circuit and a reactance in the adaptor/lamp 172. The resonant frequency is determined by component selection and is dependent on the power rating of the lamp with at least part of the reactance 172 being provided in the adaptor. This arrangement ensures that only matching lamps and adaptors may be operated in the system. Also to further improve safety a plunger (280, figure 7) may be provided to prevent exposed terminals of the adaptor being live. |
