adam2

I would be inclined to install SOME dimmers, but much fewer than in the past. Perhaps six dimmers in a village hall, a dozen in a medium size theatre and a few dozen in a large venue. It seems reasonable to plan for a LARGELY LED future, but with provision for limited use of halogen fixtures if a future production or director wants this. Incandescent lighting is going the way of gas lights and oil lamps, but is not yet completly dead so it seems reasonable to make limited provision for use of halogen fixtures. Consider also, not just "proper" incandescent theatre lanterns but any possible future need for dimming of other incandescent lamps. Incandescent fairy lights, industrial work lights, d0m3stic fixtures with GLS lamps, incandescent festoons and similar lights are reasonably foreseeable future requirements for certain productions. LED alternatives DO EXIST for most of the above, but dont allways dim reliably or well, and incandescent might be used. Good quality LED theatre lanterns that dim well are available from many suppliers, and are likely to meet the great majority of future stage lighting needs, but limited provision for incandescent seems prudent. Also the venue might be used in the future for some form of education or training, and being able to demonstrate "how it used to be done" might be useful. The more obscure types of incandescent bulb will are already hard to find, and production has probably ceased. I expect that the more common types will be available for decades yet.

AFAIK the mirror is not intended to touch the heat sink. The mirror is a dichroic type that reflects most of the light towards the stage, but transmits most of the unwanted infra red in a traight line from the lamp towards the heat sink. This raises the temperature of the heat sink, which in turn looses the heat by radiation and convection to the surroundings. Same principle as an MR16 type dichroic lamp, heat passes through the dichroic mirror and light is reflected.

One minor improvement that has probably avoided a few horrible accidents, is the almost universal use of press stud fasteners on overals rather than buttons. If a lab coat or similar garment catches fire or becomes soaked with anything dangerous, it may be QUICKLY pulled off and discarded. Not so easy with well attached buttons. (This is a good reason to wear such garments in many workshops and similar places) The general affordability of industrial laundry services and of d0m3stic washing machines has also helped by encouraging the wearing of clean overalls and other workwear, rather than garments impregnated with asbestos dust and other unknown materials. General safety standards in work places have improved greatly in recent decades. Sufficient lighting and heating. Gas safety inspections, regular inspections of electrical installations and portable equipment. Are all signs of progress. I can remember workplaces lit by gas ! . Not inherently unsafe but does require regular maintence and a bit more common sense than does electric lighting. Indoor gas lighting is now almost extinct. Factories with machinery driven by line shafting are now almost extinct. The storage and use of petrol, LPG, explosives, and firearms are now much more tightly controlled.

Agree, this should not be used. As has already been said, the laser beam should be at least 3 meters above floor level, and a greater height might be prudent. Consider the risk of someone standing on furniture for example. What about the beam exiting the room and being dangerous to someone half way up the stairs. Consider also the dangers of reflected laser beams Mirrors, shiny metal light fittings, reflective ornaments and the like. If the laser light can pass through windows, consider the risks to neighbours in upstairs rooms. In theory you Might have a room with sufficient height, no reflective surfaces, no windows, and no stairs near the room, but in practice this is a big NO.

Good point, I recall some horribly dangerous practices in schools. School theatre related, and also in metal work classes and science lessons. About 6 KW of stage lighting being used from a 13 amp plug after replacing the fuse with a solid link. Resistance dimmers open to touch. Home made extension leads of very doubtful quailty. A large school hall with no windows and no emergency lighting of any kind, entertaining in the 1970s power cuts. And the primary school that I attended in the 1960s still had open fires for heating, outside toilets, and some gas lights. This school was extended with several prefab class rooms, each with four large wall mounted electric heaters of 3KW loading, each prefab had a 30 amp submain in twin with earth cable draped around the garden. 12 KW of heating and at least 1 KW of lighting on a 30 amp circuit ! In my time at secondary school, new science classrooms were built, with new fangled ELCBs on the power circuits. It was interesting to see just how much old science lab equipment instantly tripped these new fangled devices. There was no question of wearing lab coats or even safety glasses for science lessons. Despite some over zealous elf ansafety these days, things HAVE improved considerably, in schools and elswhere. AFAIK, most buildings under government control were exampt from most safety requirements. Waterloo station had no emergency lighting when I was there in a major power failure about 1978. It is a huge area with thousands of people present and many oportunities for accidents in the dark. (the platforms had some lighting from the trains, but the concourse was very dark, being reliant on a few staff with very feeble handlamps) Major railway stations do now require emergency lighting like other public buildings.

I suspect that before the 1974 act and other modern health and safety legistlation, that most "proper theatres" were already reasonably safe. There were prexisting requirements regarding fire prooffing, safety curtains, exits, emergency lighting and related regulations. Many such regulations were introduced in response to historic theatre disasters. What the 1974 act did was largely to bring other venues up to somewhat similar standards. Circus style events, discos, nightclubs, holiday camps and like places that had previously "slipped through the net" by being "not theatres" The main change IME in theatres was a general requirement for higher standards of staff safety in workshops etc. Previous laws and regulations had primarily focused on ensuring that the assembled public got home safely with less concern about a cleaner, a barman, or a set builder suffering an accident. I recall for instance some very dangerous improvisations being employed to reach and change lamps in houselights.

You may not need a SMD fuse, if space permits use of a larger type. The correct amp rating is important, but for a non critical ELV application the design is not important.

A quick fleabay search for "120 watt par 38" turns up well over 100 results, about half of which are for the desired articles, with the others being "related" Prices from about £5 each if buying a number, up to about £10 for just one.

Yes, most other PAR lamps have gone or are going the same way. Production or import of most smaller types was prohibited under energy saving regulations some years ago. Existing stocks may be sold or used lawfully. Some larger types used primarily in the entertainment industry were exempted, but production by most major companies has ceased for want of demand. Incandescent electric lighting is going the way of gas lighting and oil lamps, both of which are still used today for certain niche purposes but are no longer mainstream lighting for homes or workplaces. A limited choice of the more common spares for gas or oil lamps are still made today. Likewise I expect that a LIMITED CHOICE of the more popular incandescent lamps will still be available in 50 years time, probably at higher prices for lower qaulity. Must go and light the oil lamp in my downstairs lavatory, to prevent the plumbing from freezing !

I suspect that manufacture or import is now prohibited, though existing stocks may be sold and used without concern. You may find that an alternative supplier still has stocks. There are several listed on fleabay, just search for "par38 120 watt" Alternatively, if current limiting rather than illumination is the object, do they have to be PAR 38s at all ? what about a pair of standard GLS lamps each 60 watts. (manufacture or import of these is also prohibited, but there are still a lot on sale, via various loopholes)

My neighbours used some for firework night. Including an effect that I not seen previously. A non electric strobe light. An effect that once ignited, burnt with an alternating briliant white flare and an almost non-luminous flame. Flashed about once or twice a second for about a minute.

Some types of LED lights do indeed use 24 volts from a transfomer, however this might be 24 volts AC in which case the lights wont work properly or at all, on DC.

I have obtained acceptable results from cheap battery operated LED Christmas lights. For most applications I would avoid the ones with a timer. These timers are NOT ADJUSTABLE at least none that I have seen are. They run for 6 hours after the batteries are inserted and then go out for 18 hours, and repeat each day. 6 hours is not in my view sufficient. The AA cells dont last long. Rechargeable cells dont work well as the voltage is lower. The run time maybe greatly extended by use of D cells instead. One option is to simply discard the included holder for 3 cells each AA and to fit instead a replacement holder for 3 cells each D size. If doing this, note that there will be a current limiting resistor (usually in the battery box) It is VITAL that this be retained in the circuit. Keet the battery holder dry or it will rapidly corrode, aided no doubt by leakage currents. Alternatively, solder wires to the three D cells, still try to keep them dry. Two sets of D cells will run the lights from early December until twelth night. This is simple and affordable if only one or two sets of lights are needed. No accuracy can be claimed WRT to run times because the lights slowly get dimmer and it is a value judgement as to how dim is acceptable before new batteries are needed. Two weeks per set of good qaulity alkaline D cells is a fair estimate. If several sets of lights are required, battery replacement becomes tedious and expensive. An alternative approach is to discard the battery holders for the AA cells, and to connect three similar sets of lights in series. TAKE CARE TO RETAIN ALL THREE OF THE CURRENT LIMITING RESISTORS IN CIRCUIT. Three sets in series may be worked from a 12 volt lead acid battery. Such batteries can deliver dangerous currents and a small fuse close to the battery is prudent. With six sets of lights (two series strings of three) a 7 amp/hour battery will last some days, and a vehicle battery a week or two. An old but somewhat serviceable deep cycle caravan battery is ideal. Think twice about about a new battery due to cost and risk of theft.

What about a bit of lateral thinking, and ordering some real* artificial* snow ? for outdoor use only. Kids love it. No mess or slip hazard indoors, and the outdoor risks are no greater than when natural snow falls. Up to a few tons can be delivered in a refrigerated truck, very large volumes are made as needed on site. No residue left when it melts, just water. Safe if kids swallow it. Outdoor play is safer under present circumstances. *Real in the sense that it is actual frozen water rather than being foam or other fake stuff, but artificial in the sense that it is made by man, not naturally occurring.

My linkI suspect that the cable pictured is covered in rayon, and not asbestos. I have seen similar on various vintage appliances. Rayon covering over rubber was popular at one time, the rayon protected the rubber from wear and improved the appearance. I would however proceed carefully, following AS A MINIMUM the precautions that I earlier suggested, just in case it is asbestos. Gloves, respirator, overalls, vacuum cleaner, work outdoors, launder all clothing and take a shower after the work.

I would certainly advise caution in the handling of asbestos, however for small qauntities I might be tempted to DIY rathar than engage a very costly specialist. I have removed asbestos covered wire from vintage theatre lanterns and other appliances. I considered the risk to be acceptable with basic precaustions. Having removed the asbestos, clean the relevant parts of the appliance with a damp cloth and then by vccuum cleaning. Wear gloves, a respirator, and overalls. Work outside. Take a thorough shower afterwards and launder all clothing worn, not JUST the overalls. Significant numbers of people have died a most unpleasant death from asbestosis, however such cases seem to be related to long term occupational exposure and not to brief, and very minor handling.

Not certain that I agree with the statement about these being a "big, dim globe" They are no bigger and no dimmer than the 60 watt GLS lamps that they are intended to replace. An unlikely choice for stage lighting, but worthy of consideration for non public areas. Decorative lighting in foyers, and functional lighting for toilets, storage areas and exit routes. Possibly also worth considering for large festoon installations. The very low loading would permit of greater lengths without excessive voltage drop. Also a saving on distro, cables, and generator capacity. About the only production lighting application that I can foresee would be small scale outdoor productions. A few dozen of these would be ample for a small basic outdoor stage, and could be powered from a vehicle via an inverter. No generator needed. No dimming needed, use selective switching instead for basic control.

Big fan of your YouTube channel, Clive. I'll grab a couple for you next week to take a look at. If you can obtain more than a couple, perhaps offer the spares for sale on this forum ? I would buy a couple.

Phillips may have some contractual arrangement that prohibits sales elswhere. That however would probably not stop grey imports whereby someone in Dubai purchases a few dozen and re-sells them on fleabay or amazon.

I suspect that the claim is true, Phillips are a reputable company and are unlikely IMHO to make false claims. Futhermore, the wattage is easy to measure, and the light output can be measured with an integrating sphere, something any university physics department should have. Rival lamp makers would also obtain samples, test them, and announce any false claims. AFAIK, 200 lumens per watt does not break any laws of physics, the theoretical limit is about 300 lumens per watt for white light, the exact figure varies according to what shade of white is innvolved. Thanks for the link, but I had already tried amazon, the lamps in question "can not be shipped to the UK" This was the case a couple of months ago, and again a few minutes ago. Does anyone have any alternative supplier ?

Phillips have introduced a new type of LED lamp with an effeciency of 200 lumens per watt, or about twice that of the best alternatives. They come in three wattages, 1 watt, 2 watts, and 3 watts, to replace 25 watt, 40 watt, and 60 watt incandescent lamps. These lamps are not dimmable but sound useful for back of house areas in venues, other busineses and d0m3stically. These lamps are primarily marketed in Dubai were a local regulation requires their use in many buildings. Does anyone know of a UK stockist ? or an overseas supplier that ship affordably to the UK ?

Before cable ties, insulating tape or pieces of string were used, or the installation was designed not to need ties. Within complex electronic equipment "lacing cord" was used. Simple equipment such as theatre lanterns or electric heaters often used rigid single core wire for internal connections that stayed in place once installed. In the case of fixed installations, then much use was made of conduit or trunking so as to minimise the amount of flexible cord. When large scale use of multiple flexible cords was unaviodable as in theatre lighting, then wrought iron hooks fixed to the building structure were used. Flexible cords could be neatly hung from these hooks and removed when needs changed, these are still sometimes used. Large armoured power cables were fixed to the building structure with cleats, and still are.

Mains voltage PAR 36 lamps were never common, have become less common, and are likely to become even less common. I would consider 12 volt lamps with a transformer for each lamp. Make certain that the transformers are suitable for dimming. Other voltages exist but 12 volt transformers are cheap and plentiful.

Carbon lamps undoubtedly withstand vibration much better than metal filament lamps, for that reason they were favoured until recently for engineers inspection lamps, on high speed printing machinery, and on warships. I would expect that they would also stand up to frequent switching well. BTW the lamps in older underground railway signals were lit continually (oil lamps originally) A compressed air mechanism pushed a green or yellow lens in front of the lamp, absence of the air supply caused a red lens to drop by gravity in front of the lamp. Metal filament lamps in the lower voltages stand up well to vibration. The main alternative to mains voltage carbon lamps was a 6 volt vehicle lamp worked via a transformer, presuming an AC supply. A carbon lamp was cheaper and simpler. 6 volt and 12 volt turn signals on vehicles survive well. 24 volt less so. Carbon lamps for general lighting of homes and workplaces "went out with the (second) war" but were still used for certain purposes as described.

I have two sources for my statement that most so called carbon filament lamps do not contain actual carbon filaments. Firstly my knowledge of electric lamps and the manufacture thereof. For a mains voltage lamp, a carbon filament is relatively short and only requires forming into a few large loops to fit into the bulb. Tungsten has a much lower resistance than carbon and therefore requires a complex arrangement to fit this long filament into the vintage style bulb. In a modern tungsten lamp this filament is coiled to render it more compact. The thicker carbon filament is much more visible than the very fine tungsten filament. Secondly, basic physics permits of determining the difference between carbon and tungsten filaments by simple measurement. Measure the cold resistance of a lamp and then calculate the hot resistance from the lamp rating. As an example consider a 240 volt, 60 watt lamp. This will draw about 0.25 amps when lit at nominal voltage. That suggests a hot or working resistance of about 1000 ohms. Now measure the cold resistance of the lamp. A 240 volt, 60 watt carbon lamp will have a cold resistance of MUCH more than 1000 ohms. A 240 volt, 60 watt tungsten lamp will by contrast have a cold resistance MUCH lower than 1000 ohms. No great accuracy may be claimed due to manufacturing tolerances, mains voltage variations and imperfect instruments, the difference in the cold resistance between carbon and tungsten lamps of similar rating is however very substantial and will swamp the above factors. Carbon lamps are also of very low efficiency and for a given wattage will be much dimmer than even a vintage style tungsten lamp, which is itself dimmer than a modern tungsten lamp. 60 watt carbon lamp=about 120 lumens. Vintage style 60 watt tungsten lamp=about 400 lumens Modern 60 watt tungsten lamp=about 800 lumens. To be strictly accurate, it was not the manufacture or import of TUNGSTEN lamps that was prohibited, it was the manufacture or import of electric lamps with less than a stated efficiency. The lamp linked to is clearly a tungsten filament lamp. Note the long and extremely fine filament.