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All about Star LEDs? Answered

I have been interested in electronics for a long time and I know many of the basics. I would like to get started with Star LEDs, but there is not much info on the internet. Here are some things I would like to know:

1. Driver to power LED - what purpose does it serve/necessary?
2. LED lenses
3. Heatsinks
4. Power supply
             -Resistors - Hooked up in parallel?
5. Any other useful info I need to know to get started with these LEDs.



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Best Answer 9 years ago

1) leds need controlled current because as a semiconductor they act as a short circuit, and thus draw 'infinite' current (as much as you can supply) which is enough to damage them. You need a driver to power them ideally.
2) most star leds have a flat emitter covered by a blob of silicone that emits light in 178 degrees. If you want to tighten this beam you have to add a parabolic reflector. If you get a reflector designed for your particular led, it will snap on, some require glue.
3) Leds put out most of their energy as heat, which destroys the diode material. You have to dump that heat somewhere or it will self destruct. Attach to something metal and you should be okay. The pictured led is soldered to a special star (aluminium) circuit board and then mounted on a heat sink. It's totally normal for the die to get above 75 degrees celcius with a heatsink on there, so bigger is better if form factor allows.
4) any way you can apply power to the driver circuit. Some drivers are designed for variable input (batteries etc) ...each instance is different.
--don't use resistors for power leds. it works for 20mA leds because they are so few and small. but when you run a 2000mA led, the resistor has to be MASSIVE, and wasteful.
5) There are good instructables, search for 'power led' and/or 'led driver'



Answer 9 years ago

Thank you so much for the response and info. I think for my first encounter with these high-power LED's, I will stick to buying a driver. Maybe later, when I become for familiar with this, I could start branching out to building my own.

I found these on eBay:
"Constant Current Regulated 1x3W LED Driver 580-600mA"


-How would I wire these? There are different types of these drivers. If I was to use batteries, what would I have to search in eBay, what are they called?


Answer 9 years ago

Oh, I forgot to ask, since we are dealing with such high current, what is the danger? For example if I want to work with a 3W 1AMP Infrared LED, what are things I should be cautious with?


Answer 9 years ago

So, those have the 2 pins similar to a regular halogen light bulb for 110-220v, direct driving from household voltage, and designed to fit in a light socket.

They are quite ideal, and consider they MAY need a little airflow/open air to not overheat.

If they are 1x3w drivers then you are best to use 3w leds (about 1amp) , designed for 600mA. IR is a bit funny because it is a low voltage led so the amperage is higher to make up for it

As said in my other response, don't rely on putting 3 1w leds in parallel to draw the current because they will be slightly uneven, and one will take more, get hotter, and then thermally 'runaway' (hotter = draw more current also) self destructing.

If you want to use batteries, you don't want these, because they are designed for household AC use. Searching 'constant current led driver' reveals a LOT of options for input and output.

I really like dealextreme.com - similar made-in-china stuff to what you'll find on ebay.

Hazards: high voltage (110-220VAC), high temperature (on some parts), and if using 3w leds, eye hazard. Just because you can't see IR doesn't mean its not dangerous, and 3 watts of IR is a ridiculously bright source of IR, ready to cook your eyeballs.