[ARC5] Halogen Light Power Supplies

[D C _Mac_ Macdonald]

But NOT having to remove and reinstall 25 screws to replace that lamp in exchange for 2.6 times the number of hours is well worth the miniscule increase of the unit cost of light produced. 
 
Pretty worthwhile tradeoff as far as I'm concerned.  It's the same reason I use 130 Volt lamps in my house.  There are still a couple of bulbs that have been in use since the house was built in 1999! 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk hotmail com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 

 
> From: brokenthumb at live.com
> To: arc5 at mailman.qth.net
> Date: Mon, 4 May 2015 12:56:40 +0000
> Subject: Re: [ARC5] Halogen Light Power Supplies
> 
> Among my collection of slide rules is a Mazda Lamp Characteristics Calculator from GE, Nela Park (Cleveland) Engineering that ‘instantly’ calculates several criteria.
> 
> If you have a bulb rated for 115 volts and apply 105 volts;
> 
> you reduce the wattage used by 13%
> 
> you reduce the light output by 26%
> 
> you increase the life expectancy by 260%
> 
> you increase the unit cost of light produced by 113%
> 
> Therefore, to get that long life you waste 13% (light output down 26% yet the wattage is down only 13%) of your dollar spent to Edison. Over the expected lifespan of 2.6 times ‘normal’ you will fork over 34 percent more money than using rated voltage (260 x 113= 294 total cost vs 260 =34%). 
> 
> Aren’t tekgnawlogy wunnerfull?
> 
> 
> 
> From: Roy Morgan
> Sent: ‎Monday‎, ‎May‎ ‎4‎, ‎2015 ‎7‎:‎57‎ ‎AM
> To: Dennis Monticelli
> Cc: arc5, Robert Eleazer
> 
> 
> 
> 
> 
> 
> On May 4, 2015, at 4:13 AM, Dennis Monticelli <dennis.monticelli at gmail.com> wrote:
> 
> > Bill,
> > 
> > I have one of those ancient lamps too.  Just put a resistor in series to
> > limit the current.  I run mine well below line voltage to insure its
> > survival.  When under-driven the light is orange and rather dim but I still
> > get a kick out of it.
> 
> Same here.  Running such  light bulb at say 100 volts or a bit less will let it last nearly forever.  There is technical information about the effect of lamp voltage on expected life - it’s a ten to the 6th power curve or some such.  The bottom line is that running a 120 volt lamp on 105 volts will let it run for a VERY long time.
> 
> The longest burning light bulb is at a fire house in Livermore, CA, and is much celebrated:
> 
> http://www.centennialbulb.org/
> 
> Happy glowing!
> 
> Roy
> 
> Roy Morgan
> k1lky68 at gmail.com
> K1LKY Since 1958