Lamps > Modern

GE Halogen "modified spectrum" A19s

<< < (2/3) > >>

lights*plus:
Medved for very frequent on-off, does a dimmer switch help to preserve the filament in a halogen lamp...turn up the light by turning up the dimmer slowly rather than with a straight on-off switch?

Mike:
I'd guess that with any filament-containing lamp, starting it at a low voltage (via dimmer) and then building up the voltage would help the lamp last a lot longer since there's not that sudden "rush" of voltage that could break the filament as it ages. I've noticed incandescents on dimmers seem to last forever (firguratively speaking of course, but even the standard 1000HR soft white lamps used  on a dimmer last longer than the extended life lamps on a standard switch.

Medved:
A dimmer will help, the "touch sensor" controller IC's (e.g. SLB0587 or so) always soft-start the lamp, although there the aim was to prevent current surges into the triac and fuse.
Otherwise with the manual dimmer, you can never turn the knob so fast it won't soft-start the lamp either...
It's just sufficient to prevent the filament to approach too close the melting point.

As the regular GLS operate farther away from the critical tremperatures, so even the temperature overshoots at the hot spots do not reach it, they do not suffer from this problem (there are lot of flashers in use, where the lamp goes complete cold between light periods and yet the lamps sustain there their complete life rating of net-time burning, so no extra degradation from the ON/OFF cycles at all).

It is practically just the halogens, whose filament is designed to operate at the higher temperature, so with the overshoot the hot spots may reach the dangerous levels.

But still I'm not sure, this mechanism is, what make the mains halogens last so short time in the real life, it is just a hypothesis.

How the dimmers help with regular GLS life is, most of them are not able to exceed 90..95% of the full power, what mean the lamps run colder. But that mean the consequence of lower efficacy, so for the same light output, more expensive electricity bill...

merc:
Linear halogens (such as Sylvania 240 V / 400 W) have their rated switching cycle only 8,000 times. (That's a switching cycle of an average/slightly better CFL.)
People used them in PIR sensor started floodlights at their houses before LEDs took their place. They were not seldom started by passerby persons or cars.
This way their lifetime was probably very short, especially in winter when the filament was being heated up from freezing temperatures.

Medved:
@merc:
The "switching cycle" rating is based on 15minutes ON / 45minutes OFF. That means during the 8000 rated cycles the lamp burns 2000 hours, what equals the rated life.  So that means all rated wear goes on the account of the burning hours.

In a similar way, regular 1000hour GLS would bear "4000 cycles" rating figure.

So the rating claims no influence of the switching alone at all.

The fact is, the real influence of the switching cycles alone could be statistically hidden behind the normal burning wear with the test cycles designed as they are.

One could wonder if those tests were not artificially designed so, the CFL's "perform" always better than the GLS...

Navigation

[0] Message Index

[#] Next page

[*] Previous page