PR bulbs have number designations assigned to them that have specifications associated with them such as current, wattage, voltage, etc. For simplicity we'll skip that and I'll just show the reference chart that came as an insert on the older Maglites. I have included this information at the end though.
PR-2 2 Cell
PR-3 3 Cell
PR-13 4 Cell
PR-12 5 Cell
PR-18 6 Cell
PR-20 7 Cell
When Mag Instrument first started out they used a generic PR (miniature flange) base bulb that was originally designed for automotive use. After some time Mag went on to produce their own line of proprietary bulbs, a first in the flashlight industry, that aimed to squeeze more run time and brightness out of a similarly sized bulb. The history of these can be found in the list below. I thought it's pretty interesting to see the increase in efficiency and lumens throughout the development of new fill gasses and bulbs. Also note that the rated voltages came closer and closer to the actual voltages put out by the cells in the light.
Argon / Vacuum Generic, for a short time from the mid 80s up until the late 80s Mag Instrument used the LPR model number and marketed these as their "Standard Flashlight Lamp".
Availability: In production
Original Run: Sourced from Philips from 1979 to ~1989
Notes: PR bulbs were designed for automotive use so no 7 Cell bulb was really available for this application. The bulb is rated for a low voltage and therefore isn't very bright.
Average Efficiency: 10 - 15 Lumen/Watt
Krypton, the original Magnum Star Bulb, design later changed to a proprietary Mag design. Stamped as MSA-1 through MSA-7 but actually a KPR bulb
Availability: In production as generic bulbs
Original Run: ~1984 to ~1992
Notes: KPR bulbs were designed for flashlights and the 7 Cell bulb was properly designed to increase life and brightness. 7 Cell lumen value is calculated
Average Efficiency: 15 - 18 Lumen/Watt
Krypton, Mag proprietary design marketed as Magnum Star and then White Star when Magnum Star was changed to denote Xenon fill.
Availability: Discontinued but NOS still available
Original Run: ~1992 to 2002 as Magnum Star and 2003 to 2012 as White Star
Notes: These are the first proprietary Mag Instrument bulbs. The rated voltages were increased to closer match the number of cells to increase life and brightness. No data available for 2 Cell as they are likely re-stamped LWSA301 or KPR102. 2 Cell lumen value is estimated.
Average Efficiency: 18 - 20 Lumen/Watt
Xenon, marketed as Magnum Star
Availability: Discontinued but NOS still available
Original Run: 2003 to 2012
Notes: I'm not sure if Mag Instrument ever produced a Xenon 7 Cell bulb. I can't find any data on one and since Xenon bulbs weren't introduced until 2003 and 7Cs were discontinued in 1989 and 7Ds in 1982 it's doubtful. These model numbers were used for the Krypton bulbs as well before they were re-branded as White Stars prior to 2003. No data available for 2 Cell as they are likely re-stamped LMSA301. 2 Cell lumen value is estimated.
Average Efficiency: 20 - 22 Lumen/Watt
Bi-Pin Xenon, Marketed as Magnumstar II
Availability: Current Production
Original Run: 2012 to Present
Notes: These are fairly new and all I was able to find was the lumen ratings. I don't think Mag has released any specs and I don't think any independent testing has been performed.
Halogen Bulbs
I should also note that although Mag Instrument never officially produced a PR based Halogen bulb (HPR) they were widely available and are still sold by some retailers. A Halogen bi-pin did come standard in the Mag Chargers. Many dealers have also sold HPRs as an upgrade to other style PR based bulbs. Shown below is an Osram, a German made, bulb that has the HPR 50 designation. It is for a 4 cell light and is one of the finest PR based bulbs available. This one is from 1983 and still gives off an amazing light. I do get the question a lot though: Why are the Halogens seemingly more expensive when based on the numbers there doesn't appear to be much benefit?
Well, the answer is that the Halogen prevents the glass of the bulb from darkening / blackening over time. The Mag Charger bulbs were designed to be especially long life bulbs intended for rugged service. If a Xenon or Krpyton bulb was used the bulb would run for so long that the filament would eventually degrade and blacken the glass leading to a reduced light output and a cloudy beam.
Quality control could sometimes be quite lax back in the day and the fill gasses were not always tightly controlled. So many folks opted to buy HPR bulbs for their lights instead of the common Krypton and Xenon models. The Halogen bulbs provided a marginally longer life but also ensured that the filament wouldn't darken the glass over time by combining with the tungsten atoms of the filament and re plating them there. This happens because unlike Xenon and Krypton, Halogen is NOT a noble gas and can combine with other atoms. The lights in turn kept a brilliant light for much longer.
This can be seen even when firing up an old HPR. The beam I got from the 1983 Osram above had very few imperfections and was a nice warm color similar to a brand new Xenon bulb. Even a new KPR on Xenon bulb doesn't give off a beam that nice. It's a shame Mag Instrument never included them with their lights because they truly are a premium bulb.
As always I'm looking to buy Vari-Beams and Vintage/Rare Mags. Please let me know if you have any, top dollar paid.
I have 2 gold plated mini mag lites made out of solid bronze, I bought them in San Francisco circa '82 at Fox Hardware on 2nd st. off Market. Came in black velvet presentation of gift cases. With clear saffire lenses. They are minimal stamped and serial numbered but MML said they never made them.
ReplyDeleteNow what ??
Very cool, you have some very rare lights. I would love to see pics if you have any, my e-mail is liftd2001@gmail.com. Maglite has grown considerably since the early 80s and most of the original folks there have since gone. Their employees are not always the most knowledgeable about their earlier products. I've gotten the same response form them when trying to find out info on old lights.
Delete