Hydrosphere UK Ltd Complete Products & Services Catalogue

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Condenser Night Filter Colour and Neutral Density Filters Colour Filters A PEL Sector Light uses colour to convey information to the mariner about his angular position relative to the light. The process of “colouring” a beam involves fi ltering out many colours and only allowing the desired colour to pass. If the fi lter does not block off enough undesired colours (wavelengths), there can be problems with the light appearing to change colour in fog. If the selection of wavelengths that is passed is too narrow, the light will not be intense enough. In Vega’s experience, the optimum transmission in coloured fi lters is about 25%. Vega uses SCHOTT optical glass for fi lters – OG 590 for red (27% transmission), and BG23 for blue-green (24% transmission). BG23 transmits almost no red or purple light. Neutral Density Filter in White Sector In a sector light having red, white and green sectors, the central white sector is about 4 times more intense than the colour sectors. When there is little or no background lighting, it is recommended that a 50% neutral-density fi lter is used for white. Although this makes the white sector twice the intensity of the coloured, the eye perceives the same intensities in all three sectors. The 50% White Filter will reduce the intensity but not change the colour. With a moderate or high level of background lighting at night, a clear fi lter glass is used in the white sector. Because background lighting at night is mostly white in colour, this gives comparable conspicuity within all three sectors. Night Filters When a sector light is used for both day and night operation, the intensity for night viewing must be reduced to between 1% and 20% of the daylight intensity for equivalent conspicuity. This Coloured Filter Projection Lens is more than can be achieved by voltage reduction at the lamp alone, without having the fi lament turn orange, and without interrupting the halogen cycle on tungsten-halogen lamps. At night in the PEL-6 Sector Light, a neutral-density Night Filter is automatically inserted into the beam to achieve this reduction. Night Filters can be made to any transmission value down to 5%. Voltage reduction at the lamp can also be used to reduce intensity down to 20% of peak output. These two reduction methods are multiplied together to calculate the resulting intensity as a percentage of peak intensity (eg 5% x 20% = 1%). Anti-Refl ection Coatings Anti-refl ection coatings increase light transmission through a lens or fi lter. PEL Sector Lights typically have 10 optical surfaces, so this becomes a useful improvement. All PEL-6 Lights have anti-refl ection coatings on all surfaces except those exposed to the lamp and the exterior. These coatings are easily damaged by cleaning, and when damaged are worse than no coating at all. Coatings are only applied to PEL-3 lights where extra performance is required. Masking of Stray Light At least 0.5% of light is scattered by the last lens surface (more if it is not clean), and becomes stray light. This can be signifi cant, especially in PEL-6 Lights of 5° subtense or less. An observer could think he is inside the beam when he is not. PEL-3 lights of small subtense are masked with a barrel extension. This is not practical with the larger apertures of PEL-6 lights. Panels can be placed some distance out in front of the light (like horse blinkers). Lamps Used in PEL Sector Lights Figure 4 M-Series Lamps PEL Sector Lights use an optical condenser system to capture light from the lamp. The condenser system picks up light from within two opposing 120° cones. Lamps which emit light mostly in two directions show signifi cantly greater effi ciency in this type of optic. The use of lamps with fl at fi laments (eg. M-series) produces 41% more intensity than standard marine lamps with vertical fi laments. Notwithstanding the above, PEL-3 lights are fi tted with standard marine lamps with prefocus candelabra bases if the required size of lamp is not available in the M-series. The PEL Sector Light is limited by the physical size of the lamp fi lament. Compact fi laments are preferred, because the larger the fi lament the larger the rest of the optic must be to capture and use the available light. This is why fi tting a larger lamp than the 250 Watt M36 lamp will not necessarily increase intensity, especially if the extra output has been achieved by enlarging the fi lament. A larger optical system would also be required, and the resultant Sector Light would be much more expensive. Flashing Constraints with M-Series Lamps M-series lamps are ideal for achieving high energy effi ciencies in a PEL Sector Light. However, the compact, low-voltage fi lament has some operational constraints which must be addressed. The fi laments have very low resistance when cold, and very high in-rush currents are experienced every time the lamp is turned on. The current can be well over 15 times the steady state current (over 150 Amps for M-28 and M-36 lamps). Lampchangers and fl ashers must be designed to carry this current. The CALC-2001 controller limits inrush current to less than 100 Amps. M-series lamps require time to warm up and cool down, as they exhibit considerable thermal inertia due to the mass of metal in the fi lament. This limits the minimum on and off-times to: M32 12V, 50 Watts 1.0 sec M28 12V, 100 Watts 1.5 sec M36 24V, 250 Watts 2.0 sec Intensity/Time graph of M36 lamp with ISO 4s (2 sec ON, 2 sec OFF) flash character imposed Figure 5 4
The effective intensity of a lamp fl ashed by switching on and off, with an onperiod of T secs duration, is proportional to T/(T+0.2). If the range is barely adequate then long on-times should be used. See Figure 5. Lamp Life and Voltage Control Virtually all PEL Sector Lights are powered by batteries, and this is the recommended approach. Batteries can be charged by mains charger, or by solar panels. The voltage from the batteries will frequently exceed the rated voltage of the lamp. Applying such a voltage signifi cantly reduces lamp life from their rated 2000 hours. To prevent inadvertent lamp life reduction the CALC controller used on all PEL Sector Lights applies pulse-width modulation to lamp power, reducing the DC-rms power as necessary to ensure that the rated power of the lamp is never exceeded. When pulse-width modulation is active, the voltage measured at the lamp by a multi-meter will not be an accurate representation of the rms voltage. Meters measuring AC-rms voltage are not effective – an oscilloscope must be used to obtain an accurate reading. Power Supplies Voltage Spikes Mains-powered battery chargers and other mains-driven power supplies must be free of voltage spikes. Power supplies with high internal inductance present a problem when used to drive low-voltage lighted aids to navigation. When a lamp fails at the end of its life, this will often occur during the current inrush at startup. The sudden drop in current from a very high value (150 Amps) to zero can induce large transient voltages (100-200 Volts) if there is any inductance in the supply circuit. This will damage controllers which are only designed to withstand voltages of the order of 40 Volts. Inductive Elements Older power supplies were built with inductive elements (chokes) which worked in conjunction with a capacitive element to smooth the pulsed DC after rectifi cation. These inductors store a large amount of energy in normal operation, and this energy generates the damaging voltage spikes. Battery Protection When initially installed and connected to a continuous battery charger, new batteries may have suffi cient capacity to absorb spikes, and they do not reach the Sector Light electronics. However, as batteries deteriorate over time this capability reduces, and spike damage to electronic equipment may start occurring. SMR Power Supplies Only Power supplies with high internal inductance are not suitable for use with neither PEL Sector Lights nor other lowvoltage lights. Switch-mode regulated battery chargers of good quality are recommended. Use the Vega VPR-39 weatherproof switch-mode power supply if in doubt. Achieving Maximum Service Life Life Expectancy Many PEL Sector Lights around the world have been in service for more than 20 years. Vega routinely refurbishes PEL Sector Lights back to new condition, which includes repolishing and recoating the optics, upgrading the electronics and repainting the exterior, for a fraction of the cost of a new light. Protection Against Moisture Ingress Users can enhance the life and performance of PEL Sector Lights by preventing ingress of moisture. This occurs whenever the light is opened for servicing, as it is otherwise completely sealed (each light holds 4 psi without leakage as a factory test). For longevity each light is best installed within a shelter, with just the barrel protruding. This reduces temperature changes imposed on the light from outside, and reduces bird fouling. Packs of properly-dried silica gel should always be left in the lampchanger area of each light between servicing, to absorb moisture introduced with each opening. Internal inspections should be no more frequent than six monthly, with twelve months being the normal. Routine Servicing Ensure lights are properly resealed after closing. Always inspect the condition and cleanliness of the O-ring seal and mating surface. Choosing a Sector Light Choice of Different Sizes Each marine port and harbour is unique, so a fl exible system is required. The PEL Light offers a range of subtenses and intensities to accommodate the constraints of each site. PEL Sector Lights make very effi cient use of solar power on remote sites. When a signal is required both day and night it is convenient if a single light can perform both functions. A light needs to be up to 5,000 times more intense during the day compared to night. The PEL-6 Sector Light has been designed for day & night operation. Two Models: PEL-3 and PEL-6 There are two models of PEL Sector Light, PEL-3 and the PEL-6. Both are available in a range of standard subtenses, from 3.5° to 20°. The PEL-3 is designed for night use, and uses lamps up to 100 Watts. Small prefocused lamps down to 10 Watts can be used where less intensity is acceptable and limited energy is available. The PEL-6 has much larger optics and is designed to meet the need for a day & night sector light. It carries a 250 Watt lamp, and automatically reduces intensity at night by two methods used together: night fi lter insertion and lamp voltage reduction. Balancing Intensity Against Subtense For a given lamp size in a PEL Sector Light, the wider the beam the less the intensity. An increase in horizontal subtense also gives an increase in vertical divergence, because the optics are circular (except with anamorphic models). Doubling the subtense will drop intensity to one-quarter (following the inverse-square law). The narrowest subtense that will meet the requirement should be used. If greater subtense or intensity is required, consider multiple lights or special anamorphic versions which spread light horizontally but keep the same vertical divergence. Choosing Individual Sector Angles For a leading line, one approach is to select a control point, like a harbour entrance. Consider the widest vessel passing the control point, and decide the width (in metres) of each sector at that point. The central white sector should be quite narrow – it is not marking the edges, but an acceptable deviation from the centre line before a colour change is seen. Use the tangent function to calculate individual sector angles. Night Intensity Reduction (Day & Night Lights) With all PEL Sector Lights, there are 6 options for lamp voltage at night, given that voltage during the day is 100%: 5
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data buoy platforms moorings naviga
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trusted by the industry Our product
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permanent marking signage Maintenan
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fog signals & detectors Visibility
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adar reflectors A range of active-p
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1.24m diameter range Available with
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Page 45 and 46: data buoy platforms moorings naviga
Page 53 and 54: jetty masts & power systems Folding
Page 55 and 56: guides the way VEGA LIGHTS MARINE A
Page 57 and 58: VLL-43 LED LINEAR LEAD LIGHT A powe
Page 59 and 60: guides the way VLB-2 LED MARINE BEA
Page 63 and 64: guides the way VLB-67 LED MARINE BE
Page 65 and 66: Program Capability • 246 flash ch
Page 69 and 70: • Programmable low voltage cutoff
Page 73 and 74: Approved for use as Class A, B, and
Page 77 and 78: Bird Spikes Sealing Stainless steel
Page 79 and 80: guides the way VLL-43 LED LINEAR LE
Page 81 and 82: guides the way VRL-91 UNI-MEGA HIGH
Page 83 and 84: INFORMATION REQUIRED FOR A VRL-91 U
Page 85 and 86: guides the way VLS-46 LED SECTOR PR
Page 87 and 88: • Separate day and night intensit
Page 89 and 90: guides the way VSL-73 PRECISION ALL
Page 91 and 92: INFORMATION REQUIRED FOR A VSL-73 1
Page 93 and 94: guides the way PEL SECTOR LIGHTS PR
Page 95: for sectored navigation lights. If
Page 99 and 100: PEL-3 SECTOR LIGHTS • Invented in
Page 101 and 102: PEL-3 Peak Intensities in White, Re
Page 103 and 104: MANUFACTURED BY VEGA INDUSTRIES LTD
Page 105 and 106: OSCILLATING BOUNDARY AND SECTOR ANG
Page 107 and 108: CALC-2001 & LOGIC INVERTER The CALC
Page 109 and 110: SINGLE PEL SECTOR LIGHT APPLICATION
Page 111 and 112: OSCILLATING BOUNDARY APPLICATIONS M
Page 113 and 114: guides the way VRL-74 LED RANGE LIG
Page 115 and 116: EASY PROGRAMMING The VRL-74 support
Page 117 and 118: guides the way VLB-36 LED OBSTACLE
Page 119 and 120: • Hard wire sync with sync delay
Page 121 and 122: guides the way VLB-92 OMNI-MEGA LON
Page 123 and 124: SPECIFICATIONS Optical Light Source
Page 125 and 126: guides the way VRB-25 MARINE ROTATI
Page 127 and 128: Mfg by Vega Industries Ltd H eriot
Page 133 and 134: All Mobilis data buoys comprise a r
Page 137 and 138: The buoys are constructed using rot
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self contained and standalone LED l
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guides the way VSU-29 GPS SYNC UNIT
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guides the way VEGAWEB MONITORING S
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Use of the VegaWeb monitoring syste
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