Some bulb questions from a "new" collector

[Fredrik]

Hi all collectors!

My name is Fredrik H?jef?lt. I'm from Sweden, but lives now in Holland. Back in the 70's I collected light bulbs, nothing special, mainly just new ones. I've always dreamt about to get one of those old, tipped bulbs. And now, thanks to internet, I've been able to get some of thoose old beauties!! But as the newbie I am, I have questions for all you experts: I have bought a Imperial light bulb with dual hairpin filaments, 16 CP, and the insulator in the base being made of porcelain. Does anybody knows about the age of this one...is it true that porcelain is older than black glass in the base? Also, does anybody have some info about the Imperial brand? And also, I've planned to try to light up the bulb, of course at a lower voltage. My question is; can I use a dimmer?? As we have 230 volts and the bulb is rated at 110 V I must lower the voltage in some manner...and I won't try anything until I'm pretty sure not to hurt the bulb!

Please, enlight me!

Regards / Fredrik

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[Tluce]

Hi Fredrik, welcome to the world of bulb collecting.  You've come to the right site.  Tim has a lot of information here.  One place you might want to start with is the timeline on the home page.  There I think you will find that a porcelain base was used around 1900 and the black glass base came into use after that.  I would definitly use a dimmer if your going to energize your lamp.  I'm unaware of the 220 v use of lighting but there must be a dimmer that can handle the volts.  Good luck, Tim

[Ed Covington]

Fredrik, as Tim Luce has mentioned, porcelain in lamp bases made a large appearance in the United States about 1900. However, General Electric started a porcelain factory in Schenectady, New York in the year 1892, and the material was used on a limited basis after that. Black glass, an invention of Alfred Swan, started to be used about 1901. The word "Imperial" was a trademark of the Bryan-Marsh Co. of NY, NY. It carried the trademark No. 38,698, which was granted on July 29, 1902. The word had been used on lamps since 1894.

[Alan Franzman]

To use a 110 volt bulb on 220 volts, you need to put a series resistance of at least equal to the bulb filament's "hot resistance" in series with the bulb.  If the wattage rating of the bulb is known, divide the square of the bulb's voltage rating by the its power rating to get the resistance value (R = E^2 / P).  This resistance will also need to have a power rating at least equal to that of the bulb.

Another method to get approximately the right power is to use a diode in series with the bulb (half-wave rectifier), but your filament needs to have sufficient thermal mass (to prevent burning out) for this to work, since you are still giving it the same voltage but at half the duty cycle.  You may notice the bulb appears to flicker with this method.

For a quick-and-dirty, but very safe, method without having to find that large odd-value resistor, I would use both a standard dimmer AND a diode, and put the dimmer in the middle of its range before energizing the bulb.

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Alan "A.J." Franzman

Email: a.j.franzman at verizon dot net

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[This message has been edited by Alan Franzman (edited March 06, 2002).]

[Andy.E]

Fredrik, i am in Germany and we have also 220 Volts. I have bought an Transformer that is connected to the wall outlet and the output can be set to 200-125-110 volts, at a maximum current of 4 amperes what should handle most bulbs  

It was about 30 ?on ebay, perhaps this helps

cu

[Fredrik]

Hi all,

I just wanna thank everybody for their info and help with my questions on the Imperial bulb. I have tested the bulb at 60 V and it lit up nicely! But...16 candlepower isn't much at all! Back then it must have been pretty "dark" even with lightbulbs.


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[Tim]

Hi Fredrik, welcome to the bulb forums!  I'm glad to see so many others help out and share their knowledge.

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Tim
Kilokat's Antique Light Bulb Site
Mountain Dew Collectibles, Volume I