adam2

I have seen a surprisingly good result in a village hall from a dozen halogen floods as used on building sites, 4 metal halide floods* and a selection of cheapo LED PARS. The halogen floods take very cheap and long lasting lamps and give a good white light. The LED PARS are fine when colours are needed for bands and musicals, and were very cheap. The only real lack is a follow spot. *Donated by myself and intended for shop display lighting, not theatre. Not dimmable. Used with the halogen site floods they give a very bright and even "neutral white" light that is ideal for filming or photography but less suited for a stage production. Used for curtain calls when fond parents want to photograph the little darlings after school plays. The lamps are under £10 each and last for years.

PAR lamps are a bit of a special case, especially the large ones, they are hard to make, the challenges being in glass working rather than being strictly electrical. Regular types of incandescent are not that hard to manufacture, they have been made for over 100 years, and I suspect that manufacture will carry on far into the future, probably of doubtful quality and at very high prices, and limited to the more popular types. And meanwhile LEDs continue to get better and cheaper.

I suspect that the more common incandescent lamps will be available for years to come, but availability of more obscure types will decline. GLS lamps are still available on line despite manufacture or import having been prohibited for some years. If incandescent fixtures see very little use, then stockpiling lamps could be considered. If use is more significant, then LEDs will pay for themselves via reduced energy use. Tungsten lighting is rapidly going the way of carbon arcs, gas lighting, and oil lamps. All of which are still used today, but are not exactly mainstream or popular lighting technologies. I can remember when the local hardware shop sold gas mantles and the more common oil lamp wicks and glasses. Such items are still available today, but only from a handful of specialist suppliers. I can remember when GLS lamps came in DOZENS of different voltages, most of them in a choice of wattages. These days the choice is much reduced. How many people these days want a 160 volt, 80 watt incandescent lamp?

Agree, EL wire is not very bright and probably unsuitable for the O/Ps requirements. To re-use the Christmas star I would either replace the LEDs or use some cheap ready made LED Christmas lights. If wiring up discrete LEDs I would use a very low AC voltage, perhaps 4 or 5 volts, and wire the LEDs in inverse parallel pairs, with a dropper resistance in series with each pair. AC is far preferable to DC in such circumstances as corrosion is less of a problem. Alternatively use cheap ready made battery operated LED Christmas lights powered either from batteries as intended, or via an ELV power supply that is located indoors. Such lights are of course DC but are hopefully better insulated than anything home made and therefore not too vulnerable to corrosion.

What about coloured LED MR16 type lamps ? Generally for 12 volts supply and only use a few watts. If the beam angle is too wide, then consider some form of improvised housing with a focussing lens, readily available in the required red and blue, thereby avoiding losses in a colour filter.

Diverging SLIGHTLY into d0m3stic matters, my bedroom is lit largely by RGB LED tape, a total of 10 meters of tape. I use it mainly for decorative effect but with all three channels on full it is sufficient for reading, and comparable in total light output to a twin 4 foot fluorescent light. The total loading of the LED tape is about 60 watts, and the fluorescent light is about 80 watts, for subjectively a bit less light.

I believe that it could be done. Use good quality bright LED tape. You may need to trial different brands of LED tape and compare relative light output. Several runs of tape per tree. Take great care with the wiring in order to minimise voltage drop. 24 volts is far preferable to 12 volts in this regard.

RS components are IME most useful for obscure or specialist items that are hard to find. Not always best value for "bread and butter" items. They are an approved supplier for most local or national government departments.

Agree that managing the lighting is a large part of the solution. If time permits, rig lanterns as initially seems best, station several observers in different audience seats and observe the prop for any unwanted reflections. If any such are observed, then turn out the lanterns one at a time to ascertain which one(s) are causing the reflections. Then decide if the lighting is acceptable without those lights, if not found acceptable then experiment with other lighting layouts or with the prop slightly differently positioned. I agree that serge is preferable to velvet, but suggest the above experiment in addition.

The voltage rating of a fuse is the highest voltage circuit in which it may safely be used. Use on a lower voltage is fine. 640 volt fuse on a 240 volt circuit=fine. 240 volt fuse on a 640 volt circuit=potentially dangerous. It may be observed in passing that 640 volt circuits are very rare, as are fuses for such a voltage. Might be a typo for 240 volts ? or misread ? Fuses for dimmers should be fast acting, type F. Whilst it is often advised that fuses be replaced "like for like" that presumes that the blown fuse was correct and not what someone had to hand last time.

Use of audio cable for DMX will almost certainly work just fine, and I would not worry about an existing small installation that is working correctly. It would IMHO be preferable to use the correct cable for new or replacement purposes. I have only once experienced a problem with cheap audio cable used for DMX and that was with a most improbable length to some distant LED PARs powered by a car electrical system. It worked fine when tested, but later picked up interference.

My suggestion was that separate lamps and reflectors might replace the large PAR lamps, similar to raylights but available in a choice of beam angles. I don't expect halogen lamps to completely vanish for decades yet, but I do expect that the choice will decline and that prices will rise. A reflector will give more options as to what lamp is used with it. We have all seen the various ways in which the ban on GLS lamps has been evaded. Similar tactics seem likely with halogen lamps.

I suspect that the large, reputable, and well known lamp companies have either stopped production of most theatre lamps, or have stopped listing them in catalogues with a view to ceasing production in the near future. That however does not mean the sudden, total end of availability. In China and probably elsewhere there are factories that can make most types of lamp to order. These may be more expensive or of lower quality than the well known brands. The large PAR lamps may be gone forever. A Chinese substitute consisting of a separate lamp, lamp holder and reflector is a distinct possibility, but a true PAR lamp is very challenging to make in large sizes.

Yes, major manufacturers are steadily cutting back on the range of incandescent lamps. Often due to falling demand rather than a ban. I can remember when GLS lamps came in DOZENS of different voltages, most of which were available in clear or pearl, and in a wide selection of wattages. These days only 110 volt and 240 volt are readily available, and many of the really odd voltages have gone forever. 140 volt, 70 watt and 160 volt 80 watt GLS lamps are no longer available except if someone finds a handful of old stock and flogs them. For a bonus point, does anyone know what they were used for ? Series street lighting bulbs are no longer manufactured. Theatre lamps that are already obscure or in limited demand will likely disappear quite soon, the more popular types might be available for decades yet, but will become expensive speciality items only available from one or two niche suppliers. Carbon filament lamps used to be cheaper than tungsten lamps but are now hugely expensive and therefore hardly used. (excluding so called carbon filament lamps sold on fleabay, that are not actual carbon lamps) I expect that production of GENUINE carbon filament lamps may have already ceased and that those on sale are old stock.

Yes, that is IMHO an often overlooked factor. Years ago when this debate started with the prohibition on manufacture or import of GLS lamps, someone said "theatres will be exempt" and I said "possibly but that wont help if manufacture ceases" Tungsten lamps are going the way of carbon arcs, gas lights, and oil lamps, all of which are still used today for specialist applications but in tiny numbers. I can remember when the local hardware shop sold gas mantles, oil lamp wicks, and replacement glasses for gas and oil lamps. Many of the more popular spares for gas and oil lamps can still be obtained, but only on-line or via mail order from a handful of specialist suppliers and not from a local shop. The end of the incandescent era is within sight. Just as gas lights "went out with the war" at least as regards new installations, and with most existing gas lights gone by 1980. Note that gas lights are NOT completely extinct, thousands remain in use, but not much compared to the hundreds of millions of electric lights. In 50 years time I suspect that tungsten lighting will still be used, but will be as rare as are gas lamps today. I suspect that the more popular replacement lamps will still be available, at high prices and of doubtful quality but still available. Less popular types of electric lamp will probably become completely unavailable.

Also, as the light is reported to be the only one in the immediate area, that might suggest some form of test or trial before installing them on a large scale. That in turn suggests that the council might inspect the sample light regularly to ascertain suitability. Any tampering might therefore be quickly noticed.

Agree, I would strongly advise against any form of tampering with the public street lighting. Especially whilst still new and therefore more liable to inspection, though not a smart idea even if old. If despite this, you are determined, I would try a deep orange colour. There is probably some ancient law whereby you can be imprisoned in the tower of London for this sort of thing though. I HAVE gelled street lights, but only short term to facilitate filming and we did have written permission to do this.

I agree that standard pine floor boards are preferable to large sheets of plywood. Whilst the PERCENTAGE expansion and contraction is probably similar, it is far less of a problem with floorboards since each one will only expand or contract minutely. When fixing the boards, leave very small gaps between them, use pieces of 0.5mm thick cardboard as temporary spacers, removing these as the work progresses. To limit warping, paint both sides of the boards before fixing, the colour of the underside is of no consequence and old, surplus or mixed paint may be used. Worn or damaged boards can be replaced as needed. Plywood can be a disposal problem at end of life, real wood may be burnt in a wood burning stove.

In my youth, I worked for a company that manufactured and serviced radio frequency heating equipment for industrial uses. The power supply for such equipment was typically several amps at several KV. I recall an order for several of the power supply units "with extra smoothing" The input was three phase and the output about 3 amps at about 2,000 volts. The intended application to supply HT to a very large audio amp. That was in about 1975, when valves were still used for some high power equipment.

I bet that members of HM forces can not cook breakfast in a frying pan heated by a skyward pointing LED par can, as has been done with the halogen ones ! I think that there is a photo of this being done

I have achieved acceptable results with a cheap stick welder purchased cheaply DECADES ago ! Just about works from a 13 amp plug, but really needs a heavier supply for serious use. Have also used a large inverter welder for a one off heavy welding job, which proved easier than I expected considering my lack of any formal training in welding.

Series street lighting in use recently. Note the relatively gradual start up as distinct from the almost instant on of a timeswitch or photocell connecting a lamp directly to the supply.

Series lighting as described above used to be more common, but is now largely confined to airfields. Series street lighting was popular in America and IIRC at least one installation remains in use. Series street lighting used lamps rated by lumens and amps, not by volts and watts. Common currents were 6.6 amps and 20 amps. Early installations used no transformers so lamps near the ends of the series strings could have a thousand volts or more to earth. Here in the UK some early street lights were carbon arcs, commonly worked in series strings of 8 to 10 arcs between outers of a 3 wire system. When high wattage and reasonably efficient filament lamps came into use, some street lighting arcs were replaced with 50 volt 300 watt GLS lamps in similar series strings, this saved altering the wiring. The filament lamps burnt for 1,000 hours without attention unlike the arcs which needed daily servicing.

Thankyou for that. We had drifted rather off topic, but at least it was not religious, political, or d0m3stic. Before the last war, many different voltages and frequencies existed in the UK. DC for lighting and power was usually 3 wire at anything from 420 volts to 500 volts between outers, though some 2 wire systems existed. DC for traction was usually 500 to 550 volts for tramways. The Southern railway used 650 volts, later increased to 750 volts. AC for domestic or industrial use used almost any voltage in the 100 volts to 250 volt range and could be derived from three phase or other systems. Frequencies included 15 cycles, 16.3 cycles, 20 cycles, 24 cycles, 25 cycles, 40, 50 and 60 cycles. The government commissioned a report known as the Weir report after the chairman of the committee Mr Weir, later Lord Weir. This recommended that all new small supplies should be at 240 volts, single phase, 50 cycles, with an earthed neutral and usually derived from 3 phase 4 wire systems at 240/415 volts. And that larger supplies would be 3 phase at 240/415 volts also with an earthed neutral. 240 volts was chosen as being about highest voltage already in general use. There was relatively little 250 volts in use. 50 cycles was chosen as being the highest frequency already in general use. There were systems operating at 60, 80 and 100 cycles, but not many. 50 cycles was also about the minimum for d0m3stic lighting. Existing DC systems and non standard AC could remain in use, and minor extensions and additions could be made to such systems, but all new systems were to be at the new standard. Implementation was much delayed by the war, and by immediate post-war shortages of labour and materials, but eventually was achieved. After the war, the 13 amp fused plug system was adopted for d0m3stic and similar purposes. These plugs and sockets were only to be used for 50 cycle AC supplies at 220/240 volts and with an earthed neutral. Where legacy DC systems, or AC at non standard voltages or frequencies remained in use, the older BS 543 plugs and sockets were to be used. The presence of a 13 amp socket was meant to indicate the presence of a standard supply into which a non technical person could pug anything with a matching plug.

DC is used throughout the London underground for traction. London underground used to have, and may still have a 33.3 cycle AC supply for signalling and other purposes. I can remember when this was used for emergency lighting at Earls court underground station. The main lighting was by large modern HID lamps mounted at high level and presumably supplied from AC public mains. In addition, smaller incandescent fittings were mounted at low level (only just out of reach) along the platforms, these used the 33.3 cycle supply. Before the war, London transport owned a large mansion block near Baker Street station. This was supplied from their own 33.3 cycle system and found little favour with the residents as this frequency is rather low for lighting, especially d0m3stically.