Jinx wrote:
>Twice this week I've had my work spotlight bulb blow when I turned
>it on. Other spotlights in the house seem to fail more often than
>ordinary bulbs, and quite regularly. And I'm sick of it. The other day
>I said I thought that cold filaments are more likely to burn out if
>power was applied at the peak of the mains cycle. Is this true ?

Clipsal make a range of soft start switches. (~ AU$20 each) They just
replace the normal light switch mech. Just starting at 0V is not enough.
You need to limit (inrush) current for the first few hundred milliseconds.
Some of the Clipsal ones have time-out functions in them too.

>Is there a simple non-PIC solution to reduce this stress or reduce the
>230V down by 10% (which would significantly increases bulb life) for
>a 60W bulb. A series resistor sounds like it should work, but are there
>any real safety concerns with a few watts of heat and/or regulations
>that prohibit this
>
>I'm peed off enough, if all else fails, to make a PIC circuit that will
>allow initial power to the bulb only at 0V (and I don't care if I don't
>break even in the long run. The satisfaction of almost never replacing
>a bulb is quite appealing right at this moment)

I have one of the timer (36 mins) ones on my outside light. It even warns
you (blinks off-on) 1 minute before the timer expires. You can also over-
ride them the same way as PIR light sensors. The timer circuit is very
small - looks like a TO-126 transistor sized package hanging off the back.

>Any comments or experiences ? One other thought was to replace
>filament bulbs with the more expensive fluorescent bulbs, although
>I've always felt they're "a bit cold"

Regards...

___________________________________________
David Duffy        Audio Visual Devices P/L
U8, 9-11 Trade St, Cleveland 4163 Australia
Ph: +61 7 38210362   Fax: +61 7 38210281
New Web: www.audiovisualdevices.com.au
New email: avd@audiovisualdevices.com.au
___________________________________________

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.