FEATURES FILAMENT REPLACEMENT LEDs - T3¼ 251 SERIES PACK QUANTITY = 20 PIECES l Direct replacement for T3¼ MES E10 l Ideal for industrial pushbutton switches and l Fully encapsulated for unrivalled vibration and shock l Bi-polar l Warm White LEDs may be used behind coloured lens as annunciator panels resistance a true replacement for a filament lamp. SPECIFICATIONS Ordering Information & Typical Technical Characteristics (Ta = 25°C) Mean Time Between Failure = 100,000 Hours. PART NUMBER COLOUR Luminous intensity figures refer to the unmodified discrete LED. LENS VOLTAGE DC Vopr CURRENT DC lopr LUMINOUS INTENSITY lv@20mA WAVE LENGTH λp OPERATING STORAGE TEMP TEMP -40 ~ +100 Topr Tstg HIGH INTENSITY 251-993-64 Warm White Water Clear UNITS 993 *Typical emission colour warm white 0.426 0.439 0.497 0.477 y 0.400 0.431 0.446 0.413 x 8-48 10 9200 * -30 ~ +85^ Vac/dc mA mcd nm 0 C Yes C 0 Intensities (lv) and colour shades of white (x,y co-ordinates) may vary between LEDs within a batch. 993 ^ = Products must be derated according to the derating information. Each derating graph refers to specific LEDs. How to Order: website: www.marl.co.uk • email: [email protected] • • Telephone +44 (0)1229 582430 • Fax: +44 (0)1229 585155 The information contained in this datasheet does not constitute part of any order or contract and should not be regarded as a representation relating to either products or service. for products or service. Marl International reserve the right to alter without notice the specification or any conditions of supply © MARL INTERNATIONAL LTD 2007 : DS 011/07 Issue 1 SAMPLES AVAILABLE Page 1 of 2 251 Series Dimensions in mm (Typical) Not to scale Colour dot on product denotes LED colour TECHNICAL INFORMATION Lamp Base Style Series Minature Edison Screw T3¼ E10 251 Metric Equivalent (mm) 10 Maximum Power Dissipation (mW) 625 DESIGN CONSIDERATIONS Single-Chip LEDs All devices feature water clear high intensity LEDs as standard. The single chip LED devices have been modified by the removal of the domed portion of the encapsulation (flat-topped) to provide even illumination of switches and annunciators. Non flat topped versions are also available, please contact the sales department for details. Product Evaluation Filament Replacement LEDs have been specifically designed to meet the primary objective of providing improved reliability. As this product range is suitable for both new-build and retro-fit, (sometimes in very old systems), a wide range of illuminated push button switches and lamp holders can be encountered. Due to subjectivity, evaluation of the LED type is recommended, (samples of all standard models are available). Care should be taken to correctly simulate operating ambient light conditions to ensure that the correct device has been selected to maximise viewing characteristics such as viewing angle, colour compatibility and on/off contrast ratio. Electro-static Discharge (ESD) Build up of electro-static discharge occurs in many situations involving people moving and handling products. The range of possible situations is very diverse but voltage levels as high as several thousand volts can and do arise in many individual situations. When an operator charged up to these levels handles a ‘static sensitive device’, there is a very probable likelihood that the device will be irreversibly damaged. It is essential that precautions are taken at all stages during manufacture and assembly of these products. Although LEDs were never considered to be static sensitive devices, changes in manufacturing technology and materials used to produce higher intensity products over a large range of the wavelength spectrum have changed this. Marl has an approved system of ESD control from goods in, through production and into final packing and despatch. We recommend all users of LED based products follow the guidelines of BS 100015. Power de-rating The forward voltage/current value of an LED is dependant upon the ambient temperature of the environment in which it is operated. Therefore, care must be taken to operate the LED at the correct voltage/current values, depending upon the ambient temperature. Consequently, a recommendation regarding operating voltages and currents is given in order to address these temperature effects. This recommendation is termed ‘de-rating’. It is usual for forward voltages and currents to be specified for ambient temperature of 25°C. However, because the values of these qualities vary with temperature, Marl should be contacted if the device is to be operated at a temperature significantly higher than 25°C. Marl accept no liability for any product that is operated higher than the stated voltage. Note: All luminous intensity figures refer to the unmodified discrete LED. How to Order: website: www.marl.co.uk • email: [email protected] • • Telephone +44 (0)1229 582430 • Fax: +44 (0)1229 585155 The information contained in this datasheet does not constitute part of any order or contract and should not be regarded as a representation relating to either products or service. for products or service. Marl International reserve the right to alter without notice the specification or any conditions of supply © MARL INTERNATIONAL LTD 2007 : DS 011/07 Issue 1 SAMPLES AVAILABLE BS EN ISO 9001:2000 Approved Manufacturer Page 2 of 2