| 摘要 |
The underwater flash light has a water-tight cylindrical metal casing e.g. of aluminium containing a low voltage lamp, a supply battery and having at least one light exit window. A halogen lamp is used, the battery supplying a voltage above the lamp's operating circuit allows preheating at a reduced voltage, which can also be used for economy operation of the lamp. Pref. a nickel-cadnium or lead-acid battery which has at least two elements mounted between two insulating plates is used for delivering either the max. voltage or an intermediate voltage for pre heating. |
