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Shin Chin LEDs

I got some Shin Chin LEDs for a project:

R9-104L-12-YD R9-104L-12-GD R9-104L-12-RD R9-104L-12-UD

What I am wondering is what is a safe and what is a maximum current for these devices. Shin Chin seems to omit any mention of these figures in the date sheet listed with mouser.

They contain 5mm LEDs. I tested them at the stated voltages. The currents measured as follows:

YD 2.0V 6.3Ma OK GD 2.0V 3.4Ma Dim RD 2.0V 6.1mA OK UD 3.0V 3.8mA OK

I suppose I would require at most 10mA of current to get a sufficient brightness from these LEDs, perhaps less.

Reply to
Fred
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You shouldn't use LEDs with a fixed voltage. The datasheet says 20 mA is safe:

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For maximum current, e.g. for pulsed applications, maybe you have to ask the manufacturer.

--
Frank Buss, fb@frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de
Reply to
Frank Buss

snipped-for-privacy@frank-buss.dehttp://www.frank-buss.de,http://www.it4-systems.de

It maybe silly, but this is the first need I have had to work with LEDs. Apparently the idea is to use a resistor to set the required current from the supply voltage.

Thanks,

Fred

Reply to
Fred

Yes, usually a resistor is sufficient. If you have a regulated fixed voltage, which could be higher than the forward voltage, try different resistors until you'll get the desired current. Usually I use half of the specified current, because modern LEDs are too bright anyway and with half the current they live longer.

If you have multiple LEDs and you really want the exact same brigthness, you can use a constant current source:

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--
Frank Buss, fb@frank-buss.de
http://www.frank-buss.de, http://www.it4-systems.de
Reply to
Frank Buss

snipped-for-privacy@frank-buss.dehttp://www.frank-buss.de,http://www.it4-systems.de

Yep, that's about what I was thinking.

Thanks for the confirmation.

Fred

Reply to
Fred

try Rseries = Vsupply - Vled /.020

Steve

Reply to
osr

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