Philips TL Mini and TL Mini Super 80
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Special TL Mini and TL Mini Super 80 fluorescent lamps Features
Lamp control gear
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Best retro purpose
Flourescent lamps are the most popular and widely used lighting source. Still widely used in most indoor environments due to their high efficiency and very good colour reproduction, flourescent lamp stocks and availability is still high. Millions of these lamps have been produced worldwide for decades. They are clearly suited for indoor lighting especially when paired with an electronic ballast that eliminates flicker and also increases system efficiency. Due to the great variety of lamps, there are some suggestions for use. Most flourescent lamps operate well at 25 degrees Celsius ambient temperature but have very low light output in freezing or below freezing environments but hot environments also reduce efficiency.
TL Mini lamps use an obsolete design that results in very poor performance. There are only very few cases where such a lighting source was satisfactory due to their short life of around 5000 hours, quick lumen depreciation due to blackening at the tube's ends and phosphorus decay due to the lamp operation. This technology can be considered a bridge between T8 and T5 lamps but nothing else. In general, except if the light source is desirable for reference or a specific effect, these lamps should be avoided.
TL Mini Super 80 lamps have been moderately improved version of the TL Mini standard lamp. Although these lamps have poor performance compared with their T8 counterparts due to the obsolete lamp gas filling that uses argon instead of krypton, their efficiency and colour reproduction is improved compared with standard TL Mini lamps. These lamps can be used on their own as accent or ambient lighting in small areas, due to their size.
Understanding manufacturer data
Lamp light output is always measured in lumens. This is a way of measuring by averaging light output at a distance of 1 meter in an integrating sphere. This was carried out in lab environments and this information was mentioned in lamp datasheets and catalogues. While this information is accurate it should be considered only across similar lamp types.
Lamp life is presented in thousands of hours. It does not point at a specific moment when an installed lamp will not operate anymore but a statistical point at which some of the lamps may not operate, giving a rough estimate of useful life.
Ra8 colour rendering index, or simply colour rendering index is a way of expressing the typical colour rendering capability of a lamp. While it may be non-intuitive this is a computed average of brightness of certain coloured samples that are light by the lamp. The brighter they are, the more efficient is the lamp in this task. Most lamps do not have a continuous colour spectra so only some specific colours might look very bright and others look very dull. Colour samples are not intense reds, greens and blues but intermediately vivid colours that are focused on human skin colours and some fabrics or surfaces, meaning that a only very high colour rendering indexes are desirable for indoor home lighting. Sun light renders colours almost perfectly, having a value of 100 while typical lamps have a rendering index between 50 and 80, a good value being above 80 and a poor one below 50.
Colour temperature is another important detail. The value is presented in Kelvins and follows a theory that boils down to the fact that light can be produced by heating a metal up to a specific temperature. A camp fire releases light as the flame reaches around 1500-2000 degrees Celsius and a slightly higher value expressed in Kelvin. The designation is warm white for a value of around 2700 Kelvin, natural white with a value of around 3200-3500 Kelvin, cool white for a value of around 4000-4500 Kelvin, daylight for a value between 5000 and 5500 Kelvin, and cool daylight for a value above 6000-6500 Kelvin. There are cultural preferences that make some warm colour temperatures preferred in colder climates and cool colour temperatures in warmer climates. The most popular home lighting worldwide is mostly warm white, due to a comfortable, pleasant atmosphere that is close to the old incandescent lamp.
Technical details
| Designation | Base | Lamp wattage | Luminous flux | Colour appearance | Colour Temperature | Colour Rendering Index (Ra8) | Life (to 50% failures) |
|---|---|---|---|---|---|---|---|
| TL Mini 4W/33-640 | G5 | 4 W | 140 lm | Cool White | 4100 K | 60 | 5000 hours |
| TL Mini 6W/35-535 | G5 | 6 W | 265 lm | (Neutral) White | 3500 K | 55 | 3000 hours |
| TL Mini 6W/33-640 | G5 | 6 W | 260 lm | Cool White | 4000 K | 60 | 5000 hours |
| TL Mini 6W/54-765 | G5 | 6 W | 230 lm | Cool Daylight | 6200 K | 75 | 5000 hours |
| TL Mini 8W/35-535 | G5 | 8 W | 390 lm | (Neutral) White | 3500 K | 55 | 5000 hours |
| TL Mini 8W/33-640 | G5 | 8 W | 410 lm | Cool White | 4100 K | 60 | 5000 hours |
| TL Mini 8W/54-765 | G5 | 8 W | 340 lm | (Neutral) White | 6200 K | 75 | 5000 hours |
| TL Mini 13W/35-535 | G5 | 13 W | 855 lm | (Neutral) White | 3500 K | 55 | 4000 hours |
| TL Mini 13W/33-640 | G5 | 13 W | 930 lm | Cool White | 4100 K | 60 | 4000 hours |
| TL Mini 13W/54-765 | G5 | 13 W | 740 lm | Cool Daylight | 6200 K | 75 | 4000 hours |
| MASTER TL Mini Super 80 6W/840 | G5 | 6 W | 320 lm | Cool White | 4000 K | 85 | 5000 hours |
| MASTER TL Mini Super 80 8W/827 | G5 | 8 W | 470 lm | Incandescent White | 2700 K | 82 | 5000 hours |
| MASTER TL Mini Super 80 8W/830 | G5 | 8 W | 470 lm | Warm White | 3000 K | 85 | 5000 hours |
| MASTER TL Mini Super 80 8W/840 | G5 | 8 W | 470 lm | Cool White | 4000 K | 85 | 5000 hours |
| MASTER TL Mini Super 80 13W/827 | G5 | 13 W | 1000 lm | Incandescent White | 2700 K | 82 | 4000 hours |
| MASTER TL Mini Super 80 13W/830 | G5 | 13 W | 1000 lm | Warm White | 3000 K | 85 | 4000 hours |
| MASTER TL Mini Super 80 13W/840 | G5 | 13 W | 1000 lm | Cool White | 4000 K | 85 | 4000 hours |
Notes:
- "MASTER" designation should point at better performing lamps but it is meaningless in this lamp range as they were normal lamps by the late 2000s;
- the 6 and 13W TL Mini lamp types were a lot less popular than the 8W one;
- Neutral white colour appearance lamps were seldomly used as the 3000, 4000, 6500 K lamps offered satisfactory variety; the 3500 K lamps or neutral white were traditionally popular in the United Kingdom;
Durability and Repair-ability
TL mini lamps fare very poorly in terms of lifespan as well as performance. Note that using an electronic ballast for TL Mini lamps does not offer a significant improvement as most are not of high quality, especially in easy to find luminaires. Starting the lamp with cold cathodes and not operating them properly can be just as bad as a classic magnetic ballast. The best service life can be achieved using electronic gear that has preheat, but they were very scarce on the entire TL Mini range so similar wattage ballasts have to be searched or recovered from PL-S, PL-T and PL-C compact fluorescent lamps.
Due to their construction, flourescent lamps cannot be truly repaired. However, if one of the end electrodes remain open due to the coil's sudden rupture as a result of a shock or any other damage, and the lamp does not have strong blackening, it can be repaired. Bridging the broken fillament lamp ends on the side that has been measured as noncontinuous with an ohmmeter, using a wire strip and soldering or careful tightening, can render the lamp operable again. However, note that the lamp is more dangerous to operate as the magnetic or electronic gear used with the lamp is stressed more to start the lamp. Some warm start electronic ballasts may be damaged if one of the lamp's end are shorted, so there is some risk involved. Lamp gears may be overheating when attempting to start the lamp for a long time, so if this occurs, consider the lamp as disposable.
Greatest features & flaws
| Features | Flaws |
|---|---|
| Low glare risk, uniform lighting | Very low efficiency except for TL Mini Super 80 lamps |
| Quite good availability | Fragile construction, poor service life |
| Mostly suited for indirect or ambience lighting | Sensitive to operating temperature |
| Quick lamp start and restart, inexpensive | Requires lamp gear |
Review
While commercial lighting was the most successful market, flourescent lamps were present also in residential and industrial environments and they were highly successful. Until the advent of advanced LED lamps, these flourescent lamps were cheap to operate and had good enough performance. The lamp's quick restart, good light stability even on conventional, magnetic gear, and reasonably simple wiring made them easy to service although the lamp bi-pin connection was prone to failure due to lamp's handling as well as normal wear, the system was reasonably easy to repair and failures were quite obvious. The sensitivity to operating temperatures, common to all flourescent lamps, limited outdoor applications as well as indoor ones where the lamp heats too much. This major drawback seriously limited outdoor applications.
TL Mini lamps are more of a niche product. While their performance is very low, making them avoidable if any efficiency or lifespan is considered, these lamps were used in signage applications and emergency lights, where they were better performing than terribly inefficient incandescent bulbs. In other aplications were compact light sources were required, the lamp was only a modest choice, as permanent lamp operation was affected by their poor service life and requirement for frequent exchanges. However, they were quite succcessful as small shoplights, designed to highlight some products at close range.
TL Mini Super 80 offer much improved colour reproduction and increased light output, while keeping the same service life shortcomings of the standard TL Mini lamps. If TL Mini lamps are desired, the Super 80 type is really the one to purchase as they perform considerably better.
Operation
All lamps require the same lamp gear that can be either conventional, composed of a magnetic, reactive or inductive ballast placed in series with the lamp along with a starter that preheats the lamp's filament to ensure reliable starts and low lamp stress. An electronic lamp gear, preferably with preheating, can be used to increase light output, eliminate flicker and increase the lamp's service life. Note that some cheap electronic ballasts do not actually offer preheating and start instantly the lamp, reducing the lamp's useful life. Preheating of lamps is assumed if there is any mention of a 0.5 second duration on the electronic ballast label or the word preheating. Most world manufacturers released electronic control gear and some products even allowed variable dimming using special protocols.
While a dimmed flouresecent lamp is not as efficient as full power operation, there were and are some environments were such flexibility is appreciated. Note that starting and operating dimmed lamps is less reliable and the temperature balance and optimum operation conditions slightly deviate in these circumstances. Overpowering a lamp is possible but it is not advised. While Super 80 lamps are best suited for these circumstance that increase light output with some reduction in efficiency and service lamps, operation in such conditions stresses the lamp. Note that operating in cold environments, as a deviation from ideal conditions, reduces lamp current and power, making the lamp slightly unstable and dim.
Suitability
TL mini lamps and especially TL Mini Super 80 lamps are highly useful as showcase light, due to their small size and preference for hotter operation, so a compact display case or fixture does not affect their output and is generally preferred.
Closed as well as open fixtures are very well suited for any lamp type. In general, open fixtures are better suited for lamps operating in warmer indoor environments while enclosed fixtures are better suited for colder environments. Despite what any datasheet may suggest, deviating higher or lower than the set 30-35 degrees Celsius lamp temperature slightly reduces efficiency. Super 80 lamps are the least affected by temperature changes as only the internal UV radiation can be influenced. TL Mini lamps are more sensitive to additional light losses due to internal coating's temperature variation than TL Mini Super 80.
History
Flourescent lamps were an evolution of clear mercury vapour lamps. Development followed two avenues to increase efficiency, low pressure mercury vapour discharge and high pressure mercury discharge. High pressure mercury discharge created more useful light but the same deficit of no red and orange light was present so the light was still unsatisfactory. Low pressure mercury discharge is very efficient but not in outputting visible light, it is on UV-light emission. This UV-light is useless if it cannot be converted to visible light.
Flourescent powders were developed to convert UV-light into visible light. Some of these powders were capable of emitting light at some wavelengths, making specific colours to be cast around but they had to be quite ressistant to UV-light and efficient. This meant that some time passed until the advent of halophosphate based colours that made possible the first daylight T12 flourescent lamps, around late 1930s. This was a major achievement as such lamps had the capability of directly competing with incandescent lamps and offer better efficiency and longer life.
Subsequent developments improved lamp life and created a wide variety of flourescent powders that cast white light with different colour appearances from warm and neutral to cold and daylight. Higher and lower power lamps were created and standardization established. The preferred lamp gear turned from incandescent ballasting or mixed light to magnetic or reactive ballasts, which improved system efficiency. In the late 1970s, following requirements for higher energy efficiency due to the world oil crisis of 1973, there were major advances in technology.
The advent of high efficiency tri-band or tri-phosphorous lamps was the most important landmark. Successful development of flourescent powders that had peak UV to visible light conversion at blue, red, and green colours with peaks near the ideal wavelengths made it possible to release lamps with specific colour appearances. This high energy in light conversion was complemented by changes in the lamps gas's fill from argon to Krypton, reducing thermal losses with a slight increase in operating voltage and starting voltage. This was the market releases of the the highly successful T8 lamp, or TL-D lamp that dominated since the early 90s. Of course, up until this time there were improvements in cathodes design and electron emmissive coatings as well as other performance enhancing solutions but the release of the TL-D lamp was the most important moment.
The TL mini lamp is especially important as development and research in this compact product allowed subsequent release of T5 lamps that had very high efficiency. Although the potential for better electrode design and gas fillings is not realized, this lamp holds an important place in the heritage of fluorescent lamps.
Manufacturing specificities
Philips flourescent lamps had very good manufacturing tolerances and the lamp's construction along with flourescent powder quality made reliable, predictable operation entirely ensured. Other world manufacturers were capable of similar performance. However, some slight differences were noticeable. For instance, Philips had slightly less powerful red phosphorus than Osram, which means that entirely equivalent lamps from both manufacturers had slightly different colour appearance. On the other side, Chinese branded lamps were much inferior in terms of flourescent powder quality and colour reproduction as well as efficiency and service life.