Hello,

I want to make a book reading LED light. Something like the one shown in the picture.



I know, the enclosure will be a big headache but I am not thinking about that now. I want to think about the electronics part first. I cannot understand, what LED should I look for? Generic 5mm white LEDs are not bright enough for reading books. What should I choose so that I can read comfortably in darkness but no one else sleeping in the same room won't be disturbed?

 

How can we possibly know that? I have no idea how much light YOU need to read comfortably in darkness. I haven't tried reading using a 5 mm white LED, but I have read material using the light from a single 5 mm red LED (though I don't know if my aging eyes would be up to it today). I also have no idea how low the light has to be not to disturb others that are sleeping in the same room. I can sleep in a room with the lights on or even bright sunlight as long as it's not directly on my face.

Why not just buy an LED book light like the one shown in the picture? It looks like Amazon has what might be that exact model for $2 (about $6 after shipping). A lot of others in the same price range. If you aren't where Amazon does business, I would imagine that there are still sources where you can get a cheap book light for less than you can build one, especially in terms of your time and effort and, especially since you already anticipate that making a suitable enclosure will be a headache.

 

How can we possibly know that? I have no idea how much light YOU need to read comfortably in darkness. I haven't tried reading using a 5 mm white LED, but I have read material using the light from a single 5 mm red LED (though I don't know if my aging eyes would be up to it today). I also have no idea how low the light has to be not to disturb others that are sleeping in the same room. I can sleep in a room with the lights on or even bright sunlight as long as it's not directly on my face.

Why not just buy an LED book light like the one shown in the picture? It looks like Amazon has what might be that exact model for $2 (about $6 after shipping). A lot of others in the same price range. If you aren't where Amazon does business, I would imagine that there are still sources where you can get a cheap book light for less than you can build one, especially in terms of your time and effort and, especially since you already anticipate that making a suitable enclosure will be a headache.

In Bangladesh, the price is minimum 500 Taka in some F commerce pages and in some reputed online shops, it's 800 Taka. That is not cheap for me. I have normal eyesight. I wear no glasses. I asked because I thought somebody in the forum may have designed book lights. If possible I will make no enclosure, only the LED with battery. And by 'not disturbing' I mean to say the light should be focused so that when it falls over the book, I can see the book clearly, but not scattered that when I turn it on, it falls on someone else's face.

 

I haven't made any "book lamps" per se but I have made several "spotlights" for different places in my home using 10-watt LED COBs a sheet of aluminum as a sink and a resistor and switch. but I do have a low voltage supply in my home so you would also need a power supply such as a wall wort.

The circuit is a basic series configuration, with the resistor calculated on the desired output of the COB. The aluminum serves as a mount and heat sink.

 

I have some Super Bright White LED's. When running at 15mA they are almost blinding to look directly at. I would imagine they would cast plenty of light on your book. As for not disturbing others - a shield or lamp shade of some sort should block most of the blinding light from your eyes and the eyes of others around you. Do you have access to SBWLED's? You might want to build an adjustable current regulator circuit to cut down on the brightness should you find that necessary.

 

I haven't made any "book lamps" per se

Back in High School - you remember those things ? ? ? I made a reading lamp using an automotive bulb and a 12 volt power supply. To regulate the brightness I shaved half the wood off of a pencil and used the carbon as a resistor. A couple paper clips to slide closer or further apart and I had a working dimmer. The pencil did get warm though. Not hot, just warm.

 

In Bangladesh, the price is minimum 500 Taka in some F commerce pages and in some reputed online shops, it's 800 Taka. That is not cheap for me.

How much would it cost you to source the parts and assemble one? I suspect that it will be more than it would cost to buy an assembled unit.

For me, the cost of buying an already assembled unit is the only way to go. I bought a used one at Goodwill and I think it cost me $1-2.

Generic 5mm white LEDs are not bright enough for reading books.

How much light do you think you need? In a completely darkened room, even the light from the indicated one might be too bright.

 

First, we know nothing about the resources available to the thread starter, nor about that individuals skills or finances.
Resources and skills are needed to do anything, and so we need more information to be able to provide any useful advice.

 

In Bangladesh, the price is minimum 500 Taka in some F commerce pages and in some reputed online shops, it's 800 Taka. That is not cheap for me.

If you don't have access to something as ubiquitous as cheap Chinese consumer electronics, what are the chances that you will have access to whatever specific LED that someone here manages to recommend to you?

800 Taka, according to an online money converter, is $6.51. If that is unacceptably expensive, how are you going to afford the parts needed to make your own?

 

I have a bin full of white LEDs that take about 20 mA @ 3.6 V.
Try one and see if it is bright enough for your purposes. If not, put another one in parallel with the first one.

 

It shouldn't take a lot of lumens to light up a printed page in the dark to where it's well enough lit to read with ease.

 

If you don't have access to something as ubiquitous as cheap Chinese consumer electronics, what are the chances that you will have access to whatever specific LED that someone here manages to recommend to you?

800 Taka, according to an online money converter, is $6.51. If that is unacceptably expensive, how are you going to afford the parts needed to make your own?

I already have a soldering kit , several generic 5mm LEDs , different types of batteries, modules and sensors that I regularly have to use. I only need to find out a suitable LED that emits enough light for reading. That's it. It's not like that I am too poor to spend 800 taka, the thing is as a single parent, I have other priorities to spend money. There is also a question in my mind like why buying if I myself can make one? Since I have posted the question here, experts will come with different advice like they're already coming. After seeing all advice, if buying looks more convenient, I'll definitely buy. No issues. I'd definitely like to know what's inside.

 

I haven't made any "book lamps" per se but I have made several "spotlights" for different places in my home using 10-watt LED COBs a sheet of aluminum as a sink and a resistor and switch. but I do have a low voltage supply in my home so you would also need a power supply such as a wall wort.

The circuit is a basic series configuration, with the resistor calculated on the desired output of the COB. The aluminum serves as a mount and heat sink.

I was also thinking about COB. However, I only found 12V COB LEDs. Since, I am looking for something that operates with lithium batteries did not find 12V COB LEDs suitable. I think I must look for COB LEDs that runs at lower voltage level.

 

Yea, you probably want a lower wattage LED of the type mounded on "star" boards.



You can get white ones with a much lower forward voltage.

 

Yea, you probably want a lower wattage LED of the type mounded on "star" boards.

View attachment 367927

You can get white ones with a much lower forward voltage.

Thank you, sir. I'd look for it.

 

I have some Super Bright White LED's. When running at 15mA they are almost blinding to look directly at. I would imagine they would cast plenty of light on your book. As for not disturbing others - a shield or lamp shade of some sort should block most of the blinding light from your eyes and the eyes of others around you. Do you have access to SBWLED's? You might want to build an adjustable current regulator circuit to cut down on the brightness should you find that necessary.

Thank you sir. I am familiar with the super bright one. However, I while searching all local online suppliers, I only see the have the generic one at present. I think super bright LED is the most convenient option.

 

Keep in mind that many "super bright" LEDs have a very narrow viewing angle, this may or may not be suitable for your usage. (30 degrees or less, some as narrow as 15 degrees, I have even seen 12)

Personally, I would be looking for something around 120 degrees or so, but that is just me.

 

I'd definitely like to know what's inside.

It's just a special purpose flashlight. A battery, LED, lens, battery compartment, and a clip. The head on the one I bought rotates near the light/lens instead of near the clip; it operates from a CR3032 battery.

 

I would buy a small LED flashlight with an adjustable zoom lens to get a feel for brightness ratings and field of illumination. If it works out, just use it and add some wires to go to an external power source such as a wall wart.

ak