: Why LED lamps consists of many small LED or grids of LED why can’t we make just one big LED light source?
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LEDs use pretty small voltages and so adding many in series can increase the voltage needed, and this means you don’t need as much current as a single big LED (or many in parallel) making the circuitry cheaper
also manufacturing plays a big role, as there is more chance of a failure happening in one big chip than in a smaller one, so production is more efficient, and then there’s the fact they only make light at the junction, so it would make a long line of light, not illuminate the whole thing, making it not very efficient at using space
We can, and we do make LED headlamps that are just one bulb.
You have probably seen it hundreds of times, and maybe not realized they are LEDS.
One reason they often use a lot of LED’s is because it opens up more design opptions, and some of those designs look cool.
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The voltage drop of a single white led is around 3.5 volts. That is independent of the size of the lead if you make it larger the current is just higher the voltage drop is the same. The only way to have a higher drop with the material we use is to have multiple LEDs in series 10 LEDs would have a 35V voltage drop
So if you power a led light from a wall socket you have 120/230V RMS and a peak voltage of 1.4x that at 170/320volts.
The circuits that produce the appropriate supply voltage is a lot simple to make if we for example have 35 LEDs in series because the voltage drop over them is 3.5*35=122V You can now power the LEDs with quite a simple and cheap component if the input voltage 120V AC. Creating lower current 122V is simpler than a higher current 3.5V from a wall outlet.
There are other advantages of multiple small LEDs. LEDs are more energy-efficient than incandescent light but still, they produce heat, and to high temperatures is something that can kill them directly or just shorten their lifespan. So multiple small LEDs spread out are a lot easier to cool than a single LEAD with the same power.
Multiple small LEDs with simpler voltage supply and simpler cooling are cheaper than a single larger LED with more advanced voltage supply and more advanced cooling
Another advantage is in general you do not what a single bright spot as the light source, spreading out the light over a larger area is something that is better in most situations. Even if the light was from a single bulb there are often diffusers in lamps so spread it out so when you look at it there is not a single bright spot. The result is LEDs in some designs are intentionally spread out to get that effect
That said there are single LEDs that can give out a lot of light. For applications where the input voltage is low like a flashlight where battery voltage is similar to the voltage drop of a single LED you can have a large single LED. LEDs for car usage where you have 12 V have for the same reason fewer LEDs than sorting your power with a wall outlet
A LED is a point source of light.
You increase the light output and use a lens (which is done), but you can only go so far as you will have trouble managing the heat generated which will also be concentrated in that point.
These lights exists, but often require cooling with a water circuit.
Using multiple light sources over a larger area helps with managing/spreading the heat and might also negate the need for using a lens.
So, it can be done, but it is not always the most suitable solution.
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