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those manufacturing the power supply and integrating it within their
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existing products.
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The power supply shall consist of a transformer, a diode bridge,
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capacitor(s) and optional voltage stabilisation device. It shall convert
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50Hz AC voltages from 207V RMS to 253V RMS to a stable DC voltage, as
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required by the LED load. The power supply shall be designed to supply
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the current requirements of the connected LED
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load.
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The power supply consists of a transformer, a diode bridge, capacitor(s)
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and optional voltage stabilisation device. It converts 50Hz AC voltages
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from 207V RMS to 253V RMS to a stable DC voltage, as required by the LED
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load. The power supply is designed to supply the current requirements of
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the connected LED load.
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The Altium PCB schematics in the zip file provided for download comprise
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three versions:
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1\) Unregulated design for a single LED (e.g. Cree XR-E)
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2\) Regluated design for a single LED, requiring the LHC4913 radiation
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resistant voltage regulator IC. This is a CERN developed part provided
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by ST and may not be available for everyone.
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3\) Unregulated design for three LED string (higher output voltage due
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to modified resistor configuration).
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Radiation resistance:
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The radiation-hard voltage regulator L4913 was developed by ST
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Microelectronics in collaboration with CERN to satisfy the radiation
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requirements of the LHC (Large Hadron Collider). Its radiation hardness
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has been extensively tested using X-rays, 60Co, and a pion beam. The
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regulator appears to tolerate TID (total ionizing dose) levels above 100
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Mrad, and 1 MeV equivalent neutron fluence above 1.9×1015 cm-2. The
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radiation resistance of the regulated designs should be equivalent to
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these levels, with the unregulated design significantly exceeding these
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levels. Luminaires based on these designs are now installed in activated
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parts of the accelerator complex and their performance is being
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monitored on an ongoing basis.
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Please note that the radiation resistance of the LED's (or other
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connected equipment) themselves, and their light output and lifetime in
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a radioactive environment, may not reach the levels of reliability
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provided by this power supply. Now that the power supply design has been
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released this is a current research topic for this
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project.
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