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Old 13th Feb 2019, 10:11 am   #7
dr_nick
Triode
 
Join Date: Oct 2018
Location: South Lakeland, Cumbria, UK.
Posts: 47
Default Re: Replacement for a 1970s IR LED [ VP

Rob,

Forgive me; there are far more knowledgeable people on the forum than me.

But if I was looking at this problem I'd be looking at the characteristic of the sensor to match the LED to, not necessarily trying to replace like for like the LED source.

Although the original LED is described as an IR device emitting a specific frequency of light (which will actually be a description of a centre value - there are several possible to choose from - of a roughly Gaussian distribution) - it will in fact cover quite a spectral range. So if you did want to use an IR LED then probably many types would in practice be close enough.

What may be simpler though, is that the datasheet for the BPW16 that I can download shows a wide spectral sensitivity. The coarse definition given is 'suitable for visible or near IR radiation' and the relative spectral sensitivity graph for the BPW16 suggests that an ordinary LED - probably of any colour - would work (as per merlinmaxwell suggestion).

Hope those thoughts help.

Nick.
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