light bulbs

I have three delco light plants[one even runs], can anyone tell me about a source for 32-volt light bulbs. Thanks in advance for any help. paulworden68@hotmail.com

Three years ago I bought bulbs from my lumber yard or HWI store. Any place that sells light bulbs should be able to order them for you, but buy 30 volt bulbs. They used the 30 volt because of the line loss. DC electricity does not travel down wires very well. It needs much larger wires to transmit electricity than AC does. When I bought mine I had to buy 12 at a time because that is the only way my dealer could get them from the manufacturer. I haven't bought any since. Railroad cabooses used 32 volt systems and they used 30 volt bulbs, and 50 watt. I have a large clear 500 watt that was in the head light of a steam locamotive. It also is a 30 volt. The last ones I priced was $6.50 each.

Good luck. "DELCO DON"

McMaster-Carr sells them. They have an on-line catalog and will sell to anyone, no minimum order.


McMaster-Carr

I have connected 3 12 volt bulbs in series. This equals 36 volts and starts my Delco 8C3 very nicely. The 12 volt bulbs are less expensive then the 30 volt ones and are available at most automotive parts stores.

If you live anywhere near a coastal harbor, many marine supply houses still stock 32 volt bulbs of different wattages as they are still used in some of the larger boats. I have seen them using standard bases just like the 120 volt lamps.

Actually Direct Current (DC), basically travels down a wire as easily as Alternating Current(AC). This is assuming the same amount of power is being transmitted at the same effective root mean square (RMS) voltage.

The advantage in a small D.C. system, is that energy can be stored in a battery bank for use when the generator is not operating.

The advantage of an AC system, is that the voltage can be changed, or steped up by a transformer to a higher voltage for transmission over distances with less loss, whereupon it can be steped down or changed to a lower voltage for use.

Edison the inventor and business man, for whatever reason, installed a DC system in New York City and later in other cities many years ago. The problem was that when transmitting power at 120 volts, the losses were so great over any real distance that he had to install a power generating station every six blocks or so to maintain a usable voltage at the consumers home.

The avoid the voltage drop over the three block distance either side of the power stations, Edison had to install huge copper wires, (or buss bars as they are called) for electrical conductors that decreased in size as they went away from the generating station. Some of these unused old copper buss bars installed underground were uncovered a number of years ago during street construction in downtown New York City.

A German scientist/engineer/mathematician named Stienmetz, who worked at the time for Edison, figured out that the same amount of power could be sent efficiently using much smaller, and thus cheaper wires if Edison changed his power system to a three phase alternating current system. Edison could then produce electricity at a lower voltage, step the voltage up to a high voltage for efficient transmission and then step it back down to whatever the customer desired, without all the usual excessive line losses.

Edison, the business man, already had a very large investment in his DC system and could not seem to comprehend the benefits of Stienmetz's AC system and so they parted ways shortly afterward.

Stienmetz soon sold his novel new idea to George Westinghouse and it proved so profitable that the DC power distribution systems quickly became a thing of the past nation wide.

Edison sent men around the country electrocuting stray dogs to show how dangerous this new AC system was. Edison was attempting to scare cities and utilities away from abandoning his patented DC system. What Edison did not bother to demonstrate to the cities and utilities, was that the same voltage DC system was just as capable of killing stray dogs as well. Edison may have been a good inventor, but he also demonstrated that he could also be a good liar in not telling the truth, the whole truth and nothing but the truth.

It is ironic that today that in some instances, the utilities generate electricity at a lower voltage AC, step it up with transformers to a very high voltage of a half million or more volts, convert the high voltage AC to DC for long distance transmission. At the other end of the line or circuit, they convert the high voltage DC back to AC and step it back down for local transmission and use. This high voltage DC goes down the long distance power lines more efficiently than the same RMS voltage AC would. The Bonniville Power Administration's (BPA) high voltage transmission line between the Pacific Northwest and California is a good example of this technology.

Then there was the guy in Buffalo New York many years ago, who tapped onto the 600 volt DC trolly car feeder circuit to light his house. He had to connect six 110 volt light bulbs in series to light his house from the 600 volt source.

The problem he ran into was that all the light bulbs had to be running at the same time, and so since he wasn't having to pay for the power, he left the lights burning all day and night. That was how they caught the guy when a neighbor got suspicious and turned him into the authorities.

Today they catch pot growers because of their high demand for electricity to run the growth lamps to make the crop flourish inside.

I thought it was Nikola Tesla, rather than Stienmetz, who promoted the alternating current. Tesla invented the AC motor and later sold the patent rights to Westinghouse Electric Company.

Your right Larry, Telsla was also smarter than Edison when it came to the practical advantages of AC power transmission and usage. I don't remember who went there first, Telsla, or Stienmetz, but these old guys were pretty smart considering the state of knowledge on the subject.

Every time I see an old generator set I fall in love with it. I would like nothing better than to have a small gas well on some property and a slow speed natural gas fired engine turning a generator (alternator) powering the house. It might not be as convenient as having utility power, but it would provide a lot more personal satisfaction.

Don't know if this one is true, but I've been told that DC current has a tendancy to make the filament of an AC bulb arc off to one side and will cause premature failure if the polarity is not reversed often. This one I know is true. If you use an AC rated 110 volt light switch on 110 volt DC current, the switch will arc across it's contacts after it has been turned off, causing the switch to burn out. I haven't had this problem with 32 volt stuff, but have had it happen at 110 volts.

Thanks for all your helpful responses. by the way I did read a book about Mr Steinmetze a long time ago dont remember that much but he was an interesting sort of guy. The reason for converting AC current to high voltage for transmission is that when you boil the equations down current is the limiting factor. I also recall seeing that most relays have current ratings for 110V Ac and 28V Dc that are the same, so it would stand to reason that 110V Ac switchs wouldn't stand up to 110V Dc since the current is flowing constantly. Thanks again for all of your help. Paul

You are absolutely correct on the business of AC ratings versus DC ratings. Many AC rated devices such as switches and circuit breakers have to be derated voltage wise when run on DC.

The AC goes through zero volts twice every cycle and this probably has some influence on how a switch functions as compared to operating it on DC.

I haven't heard anything about lamp filaments sparking or arcing when run on DC as compared to AC. Look how long a pair of car headlights will run on 12 volts DC. My boat has several 12 volt DC lamps that look just like the 110 volt lamps do and they seem to run forever. Maybe at higher operating voltages there is some effect on light bulbs when operated on DC, I just don't know either way.

Edison did have a problem with filament material slowly evaporating off the filament and plating on the inside of the glass bulb. Edison tried several things in an attempt to reduce or eliminate this problem. The Edison lamps would eventually grow dim even though the filament was still working normally. So did everybody elses lamps do the same thing.

One of the things Edison did was to mount a flat plate inside the bulb with a connection to the outside. Edison was able to measure a small electrical current between this plate and the plus side of the filament connection. He discarded this information as being not useful towards solving his immediate problem and thought the effect was just a curiosity.

What the businessman tinkerer Edison did was to miss out on the honor of having invented the first vacuum tube rectifying diode. That honor went to an English fellow who's name was John Ambrose Fleming and his Fleming Valve tube. Edison was a pretty smart cookie, but he did miss a shot every now and then.

Getting back to AC versus DC ratings, I would generally rate an AC device like a switch operating on DC as having the same current rating, but maybe only 1/3 the voltage rating to interrupt the current. One has to be careful when using electrical devices out of their intended design criteria. I have used a number of AC rated curcuit breakers (Hienman brand) on low voltage DC circuits and have had no problems doing it this way. This is with both the magnetic and thermal style breakers. The magnetic types do not work so well on large lamp loads as the in rush currents are enough to trip the breaker. (two 55 watt 12 volt DC flood lamps to be exact.) I changed these magnetic breakers out with the thermal type breakers of the same ratings. I could protect the circuit current wise at a closer value to the operating current of the lamps. I have never had a problem with arcing contacts in these breakers operating on 12 volt DC rather than their rated 120 volt AC rating. At higher Dc voltages, there would be a problem.

Oh yes, the problem of light bulbs turning black on the inside is still with us today, but probably not as bad as it was back during Edisons time. Maybe it is the AC operation today rather than Edisons DC operation that did the trick.

The way it was explained to me, AC bulbs have a lighter filament than DC bulbs. The effect of the DC current on the lighter filament is to push it out in an ever increasing arc until it eventually breaks. Reversing the polarity supposedly will reverse this process. Like I said ./ I don't know if it is true.

I have never heard of an effect on light bulbs such as you mentioned. That doesn't mean that it doesn't happen, I just do not know.

A light bulb designed for 110 volt operation will have a constant polarity 110 volts applied across its terminals when operated on a DC circuit.

The same light bulb when operated on a 110 volt AC circuit will have an alternating plus and minus 172 volts applied across its terminals at whatever the frequency is, usually a 60 CPS sine wave here in the U.S.of A.

The AC voltage is usually measured as the RMS value of the peak sine wave voltage and would be 110 volts AC in this example. While the power in watts would be the same in either case, there obviously could be some measurable difference in the operating conditions of the light bulb on DC as compared to operating it on AC.

I have just never read, or heard about the effect that you refered to and therefore have never looked into it. That don't mean it don't happen.

[Steve Cunningham]

If you need some 32V light bulbs, I probably have some. I have collected antique light bulbs for years. I seem to remember buying a dozen or so 32V bulbs with the tips on the end. Steimetz was an interesting fellow. Came here and barely got through Customs. He was a hunchback, and in very poor health. He was a mathematical genius. He got a job as a draftsman at a dynamo maker. Before long he was designing the dynamos, better. He came to the attention of General Electric. They offered Steinmetz a job. Steinmetz declined. He said when he got here, the man who owned the dynamo company took a chance and gave him a job. If that man were loyal to Steinmetz, Steinmetz would be loyal to him. GE doubled their offer. Nope. Finally, GE bought the Dynamo maker to get Steinmentz.

[Andrew Mackey]

There was a thread on DC bulbs and lighting last year. Look it up on the Stak Archives. The AC 110 volt bulbs will curve the filaments. I use them on my 110 VDC Kohler model C plane, because the 110 VDC bulbs are so expensive. To get around the filament curvature problem, I reverse the + and - leads to my lights every time I hook up the generater. The bulbs last 10 times longer, than if I dont reverse the power.
Andrew

[agsem]

My first career was US Merchant Marine Engineering Officer. Until the 1950's, most ships built were 240/120 VDC. I just pulled out my 1969 Mariners Annual, from which we ordered consumables, and see light bulbs are not specified ac or dc. Most are 120 volt, tho some are available in 230 volts. We used RS - Rough Service and VS - Vibration Service rated bulbs.

[Billy J Shafer]

Gee Paul sure glad you did not ask to buy a car.Ask for light bulbs and got a history lesson.

[Elden DuRand]

Frank and I are restoring a 32-Volt Delco plant and needed some 32 Volt lamps. He shopped around for price and found the following outfit who shipped us 20 100 Watt 32 Volt medium base (regular screw-in) lamps.

Here's the address and phone number:

ABI/Precision Lighting
3635 Standish Ave
Santa Rosa, CA 95407
(707) 585-6210 / (800) 422-1301

Hope this helps.

Take care - Elden
http://home.cybertron.com/~edurand

[Jack Hottel]

One time I saw a high speed motion picture of a light bulb filament as it was turned on. It takes finite amount of time for the filament to heat but the magnetic action starts immediately! The filament was in the form of a fine coil and 60Hz current could easily be seen as the coils attracted/repelled each other. The action is so violent one wonders how the filament holds together. Of course the current is high until the filament heats up. It is no wonder that most filament failures are on turn on!
Jack Hottel

[Fred M.]

Originally Posted by Guy (GUS) Simms

The way it was explained to me, AC bulbs have a lighter filament than DC bulbs. The effect of the DC current on the lighter filament is to push it out in an ever increasing arc until it eventually breaks. Reversing the polarity supposedly will reverse this process. Like I said ./ I don't know if it is true.

Guy-

This rings a bell. I recall hearing years ago about light bulbs failing sooner when operated from DC.

A great amount of effort was expended investigating the effect. Apparently a notch is formed in the filament. The notch continues to grow, and at some point mechanical shock will be sufficient to make the filament break at the notch. Often the necessary shock occurs when a cold lamp is turned on. The notch effect is only observed for lamps operating from direct current.

I did a quick search and found a reference to the problem at http://www.harison-toshiba.com/lampinfo.htm. Near the bottom of the page, there is a discussion entitled "Lamp Life (AC vs. DC)". They don't explain why the effect doesn't happen to AC lamps!

Fred

[armandh]

Originally Posted by Bill Cole

I have connected 3 12 volt bulbs in series. This equals 36 volts and starts my Delco 8C3 very nicely. The 12 volt bulbs are less expensive then the 30 volt ones and are available at most automotive parts stores.

OR FIVE 6V BULBS FOR YOUR CHANDELIER