| 摘要 |
A Method and an arrangement providing detection of deteriorated lamp filaments (3) in a lamp circuit (11) fed by constant current, in particular for a lamp supervision system for airfield lights. A change in a constant current fed through a lamp circuit (11) is initiated, whereby the lamp filament resistance is determined once in conjunction with the change in current and once a time period later. A difference between the resistance determinations constitutes the deterioration of a lamp filament (3) in comparison with a threshold value. Hence, no record of previous resistance determinations have to be stored, and lamps (4) can be replaced when the difference matches the threshold value. |
