All devices feature water clear high intensity LEDs as standard. The single chip LED devices have been modified by the removal of the domed
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
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
can be encountered. Due to subjectivity, evaluation of the LED type is recommended, (samples of all standard models are available). Care should
portion of the encapsulation (flat-topped) to provide even illumination of switches and annunciators. Non flat topped versions are also available,
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
and despatch. We recommend all users of LED based products follow the guidelines of BS 100015.
Power de-rating
wavelength spectrum have changed this. Marl has an approved system of ESD control from goods in, through production and into final packing
care must be taken to operate the LED at the correct voltage/current values, depending upon the ambient temperature. Consequently, a
termed ‘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,
recommendation regarding operating voltages and currents is given in order to address these temperature effects. This recommendation is
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.
