Q5 XR-E Maximum Voltage Question

[556man]

Hello,

I got this from DX.

http://www.dealextreme.com/details.dx/sku.2394

It says 3.7V typical driving voltage. I tried 3 AA eneloop and it worked fine. Just wondering what's the maximum voltage on this emitters before it goes

Thanks in advance for the info.

556man

 

[Mr Happy]

Ask not about the voltage, ask about the current. LED emitters are current sensitive devices. As per the specifications, the maximum current is 1000 mA, but I think that depends on how much heat sinking you provide. I dare say it would go if you fed 1000 mA through it without providing sufficient cooling.

If you provide really good heat sinking you can in some cases rely on the internal resistance of the battery to limit the current to a safe value, especially when the nominal battery voltage is about 3.7 V.

 

[556man]

Ask not about the voltage, ask about the current. LED emitters are current sensitive devices. As per the specifications, the maximum current is 1000 mA, but I think that depends on how much heat sinking you provide. I dare say it would go if you fed 1000 mA through it without providing sufficient cooling.

If you provide really good heat sinking you can in some cases rely on the internal resistance of the battery to limit the current to a safe value, especially when the nominal battery voltage is about 3.7 V.

Thank you Mr Happy for the info. I'll keep the current under 1000 mA to be on the safe side. I'm making a cree candle for my brother and sister in the Philippines. They live in the provinces where there are always blackouts especially when a hurricane passes by. I guess this is better than using a candle. I'm using a 3 cell battery holder to power the emitter. It's plenty bright but only last a couple of hours runtime. I was thinking of putting some driver on it with a low medium and high setting to increase runtime but have no idea how to install it on the heatsink. The heatsink is from a PC processor.

Thanks again.

556man