Philips HPL-N
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Standard High Pressure Mercury Lamp with 50W, 80W, 125W (E27 base) and 125W, 250W, 400W, 700W, 1000W (E40 base) Features
Lamp control gear
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Best retro purpose
Mercury vapour lamps were traditionally used on industrial and street lighting and they can be used on these areas although LED lamps offer much better performance with lower energy consumption. There are still some specific uses that are specific to this technology. Light appearance is cool white with a bias towards reds as well as blues, and, especially ultraviolet.
Although this is rarely specified or even mentioned in datasheets, UV-A emission is significant if the lamp is used as is, with no cover. This means that most surfaces that are painted white look even whiter in this light. Trees foliage is also emphasized, so this type of lamps are very well suited in gardens. Flowers are not as well showcased as some colours are missing except for red, orange, white, blue and violet. The amp themselves do release quite a lot of heat meaning that closed fixtures are not well suited if not specifically built for this purpose.
Houses can be properly light but such a lamp is less suited for living rooms, bedrooms but is well suited for workshops, halls or any other space that requires wide area lighting. Generally, low power lamps such as 50W are to be avoided as they are quite fragile so typical applications focus on 125 and 250 watt lamps and 400, 700, 1000W lamps are typically too large or cumbersome to be used as free standing lamps or in light fixtures. Due to the fact that fixtures are getting harder to find, outside applications such as area lighting should consider a minimal protection for lamps, meaning that floodlighting is harder than in the past. Of course, any metal-hallide and high pressure sodium fixture can be adapted, if found.
Benchmarks
Durability and Repair-ability
Generally, mercury vapour lamps were very durable but more modern products were released with lower typical lifetimes. This is mainly due to the fact that upto the 70s, even into the early 80s, manufacturers focused on better performing lamps but this was detrimental to sales. Many installations were left as is with extremely old lamps that were still working, despite very low light output with a greenish tint, since they were not turned off and repairing them cost more than leaving them as is. Also, keep in mind that electricity was very cheap at that time. Many lamps could still operate with broken outer bulbs and left to be blown by wind, cope with mist and frost, although they were dangerous due to UV-C output.
Compared with modern LED lamps, mercury vapour lamps fare very poorly, as they have noticeable light output and quality degradation over 10.000 hours. However, they do have advantages. Hot or cold air affects them very little and they can survive direct operation in free-standing position, meaning with the lamp suspended on wires, even for their entire operational life. Ballast can survive tens of years if properly protected against direct rain or snow exposure. A very simple circuit means that lamp servicing is straightforward and risks are similar to mains voltage operation. 125 and 250 watt lamps are very well built and they were highly popular.
Greatest features & flaws
| Features | Flaws |
|---|---|
| High light output in very compact package | Serious risk of glare |
| Highlights white walls and gardens | Not suited for main interior light |
| Mostly omni-directional light | Unavoidable light flicker and some heat output |
| Very simple circuitry and operation | Requires bulky, heavy lamp gear |
Review
A midrange, quite slim, business laptop, released in 1998. It had an average mix of parts. Perhaps the single biggest issue is that the whole Dell CP and CPi range is very complex and difficult to understand. Differences between CP and CPi models is minimal in terms of aesthetics while most configuration options are difficult to spot. The major performance jumps are shown in the CPi lineup that has a Pentium II CPU model with major performance improvements, although the Pentium I option is still decent. The graphics chipset is quite fast, actually the best among Pentium I laptops, with good Windows acceleration and compatibility. Another rare feature is the presence of USB ports on a Pentium I era laptop, which is very nice and useful.
However, the typical mix of features of these laptop models mean that it also was obsolete by late 1998, just as most of the mid and high end IBM laptops, due to a lack of 3D acceleration. Windows 98 SE is a typical choice, especially if you have at least 32MB of RAM available. The Neomagic graphics is the top performer on 2D graphics both for compatibility as far back as Windows 3.1 and DOS as well as competitive with Chips&Technology or S3 Trio 64 videocards.
The LCD TFT screen is somewhat alright but far from being the best in terms of contrast and colour reproduction. However, the screen's brightness can be quite pleasantly set using keyboard shortcuts, as the laptop has somewhat more levels to choose from. As usual, DSTN or passive matrix screens should be definitely avoided due to their poor contrast, response, colour reproduction and brightness levels, no matter how lightly they were used.
The keyboard is not as pleasant to use as some IBM models, feeling somewhat light on keypresses. The palmrest is comfortable although the trackpad is somewhat bad in terms of sensitivity and response, being quite dependent on ambient humidity, as is also mentioned in the operating manual. The choice of a trackpoint system would have been much better. Also, due to the laptop's design, the lower area near the mid part of the laptop's case, between bays, is a common failure point due to the simple screw mounting point with no additional stiffening brackets.
The removable drive tray is a nice feature, offering both CD-ROM and Floppy drive support, which was a staple of period DELL laptops . The rechargeable battery has an unique self test feature that also shows the charging level by a simple button press. The BIOS and suspend battery uses a set of non-standard NiMh cells that can be quite messy if worn enough.
The lid closing latch is quite badly designed as it compounds the issue with cracks midway on the palmrest and cases's edge. The display's case is quite flimsy although the frame itself is reasonably well engineered. The integrated speakers are somewhat poor despite their positioning and size, being quite prone to failures due to water ingress.
The standard HDDs are quite competent in terms of size and performance, being well accustomed to the rest of the laptop's configuration.
Software support is great for reasonably modern (for its time) operating systems. Due to the video chipset, Windows 98 is the best operating system choice. Good DOS sound support is present due to the CrystalWare audio chipset that is Sound Blaster compatible, offering good MIDI and software support in MS-DOS.
Manufacturing specificities
Philips has been producing lamps for many decades. Lamps produced in the 70s and early 80s are probably not commonly found today. In the 90s and early 2000 Philips was manufacturing lamps in Holland and other countries, while in the last years they were doing the same thing in China. Quality was not severely affected as, realistically speaking, there were some occasional lamp defects even in their Holland produced lamps due to average manufacturing quality. It should be noted that mercury vapour lamps were mass manufactured and considered low-cost products, meaning that quality was not paramount.
Until the manufacturing plants move to China, there were small differences in this product line as the 90s and early 2000s was using the same technology. Chinese built lamps have some slight improvements that leave some aspects to be desired as well. The internal coating is thinner and has a different grain size with a potentially different powder mix, improving colour rendering more than what the datasheet suggests. Lamp lumen maintenance and uniformity is improved due to a thinner coating that degrades slower and more uniformly. However, the lamp light looks whitish-green rather than whitish-purple, which might be unpleasant for some persons.
Products manufactured by Philips were similar to General Electric but with a quality and consistency much above some East-European manufacturers in terms of colour rendering, light output and life. However, Philips was manufacturing lamps with shorter lifetimes and poorer internal coatings than Osram ones, even if some values specified in datasheets might not suggest much. These differences were maintained until the end of Mercury Vapor lamp production in the late 2010s. This Philips-Osram lamp difference must be experienced in person. On the other side, Philips lamps were much more popular and are easier to find.