Lielākā daļa NDIR miniatūru un subminiatūru vakuuma spuldžu ir paredzētas 5 V, maiņstrāvas, nepārtrauktai darbībai. Lampu kalpošanas laiku nosaka, izmērot ļoti lielu lampu partiju un reģistrējot, kad 50 procenti lampu neiedegas.
Bieži vien, lai pagarinātu lampas kalpošanas laiku, pielāgota shēma tiks izstrādāta, lai pārveidotu no nepārtrauktas darbības uz impulsu. Pulsējot lampu (to izslēdzot un ieslēdzot), tiek samazināts lampas degšanas laiks paraugu ņemšanas laikā, tādējādi pagarinot lampas kalpošanas laiku.
However simply pulsing the lamp without insuring proper design to protect from inrush current can actually cause premature failure. When the filament is cold and has much lower resistance, thermal shock can cause a fracture in the filament. This happens when power is applied and there is a surge of current which causes rapid expansion of the tungsten, along with thermal shock. Over time, the filament becomes thinner and more brittle and eventually experiences premature failure due to in rush current damage.
When designing the lamp power circuit there are a few commonly used methods to prevent damage from inrush current. The first is called simmer voltage. When using simmer voltage, a small amount of power is supplied to the lamp in the off cycle; typically just enough to keep the filament warm and reduce the impact of inrush current.
Otrais ir palielināt jaudu, līdz tiek sasniegts maksimālais/optimālais gaismas jaudas līmenis, nekad neizmantojot visu jaudu uzreiz.
And the third is to add a circuit that prevents the lamp from drawing additional current, or restricts the amount of additional current that can be drawn at start up.
Life hours is a critical factor when selecting an NDIR lamp. Understanding all contributing factors that affect a lamp's life, coupled with proper system design can greatly impact the life of both the lamp and the system it is designed into. For more helpful information on NDIR lamps, visit our Technical Notes page here.
