208 series
features
• Direct replacement for T6.8 Slide Base
• Flat topped for enhanced, even illumination of large lens
areas
• Water clear lens
• Durable to shock and vibration
• Ideal for industrial pushbutton switches and annunciator
panels
• Pack Quantity = 20 Pieces
specifications
Ordering information and typical characteristics (Ta = 25°C)
Part
Number
208-501-21-38
208-521-21-38
208-532-21-38
208-930-21-38
208-997-21-38
208-993-21-38
208-501-23-38
208-521-23-38
208-532-23-38
208-930-23-38
208-997-23-38
208-993-23-38
Colour
Red
Yellow
Green
Blue
White
Warm White
Red
Yellow
Green
Blue
White
Warm White
Voltage
Vac/dc
12 Vdc
12 Vdc
12 Vdc
12 Vdc
12 Vdc
12 Vdc
24-28 Vdc
24-28 Vdc
24-28 Vdc
24 - 28 Vdc
24-28 Vdc
24-28 Vdc
Current
DC
(mA)
20
20
20
20
20
20
20
20
20
20
20
20
Luminous
Intensity
(mcd)
600
600
800
140
27000
Call
600
600
800
140
27000
Call
Wave
Length
(nm)
630
585
515
465
* See below
* See below
630
585
515
465
* See below
* See below
Operating
Temp.
(°C)
-40 - +80
-40 - +80
-40 - +80
-30 - +85
-30 - +85
-30 - +85
-40 - +80
-40 - +80
-40 - +80
-30 - +85
-30 - +85
-30 - +85
Storage
Temp.
(°C)
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
-40 - +100
De-rating
Graphs
D
D
F
U
I
I
D
D
F
U
I
I
* = Voltage for 20mA product is Vf at 20mA, not Vopr
- Products must be de-rated according to the de-rating information. Each de-rating graph refers to
specific LEDs. Please refer to graphs on page 2.
- Luminous intensity is measured at 20mA on a discrete LED unless otherwise stated.
to order
to order please contact us on: t:
+44 (0)1229 582 430
f:
+44 (0)1229 585 155
e:
sales@marl.co.uk
w:
www.leds.co.uk
© marl international limited technical documentation has been designed by marl international limited for the
intention of providing information, which must not be copied or released to a third party without prior
written consent from marl international limited. the information provided does not constitute part of any
order or contract and should not be regarded as a representation relating to either products or service. no
responsibility can be assumed for inaccuracies or printing errors. marl international limited reserve the right
to alter without notice the specification or any conditions of supply for product or service.
BS EN ISO 9001:2008
approved manufacturer
marl international limited - dsn 208 - version 2012-12-06-113449
page 1 of 5
filament replacement leds
208 series
technical data
42.60
7
5
+ Printed on base denotes Anode. Colour
dot on product denotes LED colour.
Dimensions in mm (typical)
Not to scale
Lamp Base Style
Series
Metric Equivalent
(mm)
Max. Power Dissipation
(mW)
T6.8 Slide Base
997F-C
x
y
0.31
0.32
208
-
899F
-
-
x
y
625
*Typical emission colour Warm White
0.4255
0.4000
0.4390
0.4310
0.4680
0.4385
0.4519
0.4086
*Typical emission colour White
-
-
-
-
Intensities (Iv) and colour shades of white (x,y co-ordinates) may vary between leds within a batch
de-rating information
Derating Graph D
55
50
45
40
35
55
50
Derating Graph F
55
50
45
40
35
Derating Graph I
Forward Current IF (mA)
Forward Current IF (mA)
40
35
30
25
20
15
10
5
0
0.0
20.0
40.0
60.0
80.0
100.0
Forward Current IF (mA)
45
30
25
20
15
10
5
0
0.0
20.0
40.0
60.0
80.0
100.0
30
25
20
15
10
5
0
0.0
20.0
40.0
60.0
80.0
8.5
100.0
Ambient Temperature Ta (°C)
Ambient Temperature Ta (°C)
Ambient Temperature Ta (°C)
to order
to order please contact us on: t:
+44 (0)1229 582 430
f:
+44 (0)1229 585 155
e:
sales@marl.co.uk
w:
www.leds.co.uk
© marl international limited technical documentation has been designed by marl international limited for the intention of
providing information, which must not be copied or released to a third party without prior written consent from marl
international limited. the information provided does not constitute part of any order or contract and should not be regarded as a
representation relating to either products or service. no responsibility can be assumed for inaccuracies or printing errors. marl
international limited reserve the right to alter without notice the specification or any conditions of supply for product or service.
BS EN ISO 9001:2008
approved manufacturer
marl international limited - dsn 208 - version 2012-12-06-113449
page 2 of 5
208 series
de-rating information continued
Derating Graph U
55
50
45
40
35
Forward Current IF (mA)
30
25
20
15
10
5
0
0.0
20.0
40.0
60.0
80.0
100.0
8.5
Ambient Temperature Ta (°C)
to order
to order please contact us on: t:
+44 (0)1229 582 430
f:
+44 (0)1229 585 155
e:
sales@marl.co.uk
w:
www.leds.co.uk
© marl international limited technical documentation has been designed by marl international limited for the intention of
providing information, which must not be copied or released to a third party without prior written consent from marl
international limited. the information provided does not constitute part of any order or contract and should not be regarded as a
representation relating to either products or service. no responsibility can be assumed for inaccuracies or printing errors. marl
international limited reserve the right to alter without notice the specification or any conditions of supply for product or service.
BS EN ISO 9001:2008
approved manufacturer
marl international limited - dsn 208 - version 2012-12-06-113449
page 3 of 5
208 series
also available
Part numbers also available in the 208 series:
Part
Colour
Number
208-501-22
208-501-22-38
208-501-24-38
208-501-48
208-514-22
208-521-04-38
208-521-22
208-521-22-38
208-521-23
208-521-42
208-532-22
208-532-22-38
208-532-24
208-930-22-38
208-993-22-38
208-993-24-38
208-993-42-38
208-993-48-38
208-993-50-38
208-997-22-38
208-997-24-38
208-997-26-38
208-997-48
208-997-48-38
208-997-80-38
Red
Red
Red
Red
Green
Yellow
Yellow
Yellow
Yellow
Yellow
Green
Green
Green
Blue
Warm White
Warm White
Warm White
Warm White
Warm White
White
White
White
White
White
White
Vopr
24 Vdc
24 Vdc
48 Vdc
60 Vdc
24 Vdc
20 mA dc
24 Vdc
24 Vdc
28 Vdc
15 Vdc
24 Vdc
24 Vdc
48 Vdc
24 Vdc
24 Vdc
48 Vdc
15 Vdc
60 Vdc
125 Vdc
24 Vdc
48 Vdc
230 Vdc
60 Vdc
60 Vdc
60 Vac 50 Hz
Voltage
The products listed above illustrate all of the options available to order. These products may have custom modifications that
alter their operation beyond the generic information contained within this datasheet. Please contact sales for further
information.
RP = Reverse Polarity
to order
to order please contact us on: t:
+44 (0)1229 582 430
f:
+44 (0)1229 585 155
e:
sales@marl.co.uk
w:
www.leds.co.uk
© marl international limited technical documentation has been designed by marl international limited for the intention of
providing information, which must not be copied or released to a third party without prior written consent from marl
international limited. the information provided does not constitute part of any order or contract and should not be regarded as a
representation relating to either products or service. no responsibility can be assumed for inaccuracies or printing errors. marl
international limited reserve the right to alter without notice the specification or any conditions of supply for product or service.
BS EN ISO 9001:2008
approved manufacturer
marl international limited - dsn 208 - version 2012-12-06-113449
page 4 of 5
208 series
design considerations
Single-Chip LEDs
All devices feature water clear high intensity LEDs as standard. In devices where discrete LEDs are used, 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.
Flat-topping does not apply to devices using surface-mounted device (SMD) LEDs.
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. Marl 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.
to order
to order please contact us on: t:
+44 (0)1229 582 430
f:
+44 (0)1229 585 155
e:
sales@marl.co.uk
w:
www.leds.co.uk
© marl international limited technical documentation has been designed by marl international limited for the intention of
providing information, which must not be copied or released to a third party without prior written consent from marl
international limited. the information provided does not constitute part of any order or contract and should not be regarded as a
representation relating to either products or service. no responsibility can be assumed for inaccuracies or printing errors. marl
international limited reserve the right to alter without notice the specification or any conditions of supply for product or service.
BS EN ISO 9001:2008
approved manufacturer
marl international limited - dsn 208 - version 2012-12-06-113449
page 5 of 5
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