Introduction: LED Bookmarker +table Lamp (with Brightness Control)
This is a DIY reading light . I call it " LED bookmarker".
I have created a bookmarker that helps us in reading the books in dark .It an used as table lamp , shared, it is so bright that two people can read read books comfortably (when used with full brightness)
this bookmarker has some LEDs to give light . it is big when compared to other book markers ,but worth it.
I got this idea when i started reading a book and suddenly lights went off , there was a bookmarker sitting just in the middle of two pages doing nothing!! , i wanted it to help me.
LED bookmarker can be used in hostels , while camping outdoor or on the bed , when you dont want to disturb others.
its brightness can be controlled.
Step 1: Things From Collections
- plastic sheet / metal sheet (any sheet for bookmarker )
- LED strip , pure white( should be bright enough and slim )(I prefer the one without waterproof coating)
- old mobile phone with battery or any battery pack or AA or AAA rechargable batteries
- potentiometer of least value available ( i have used 1k)
- single strand wires ( copper wire with little spring action and alumminium wire)
- m-seal (something like sugru )
- cellophane tape
- soldering iron
- wire strippers
- hack saw
- glue gun
- screw driver
Step 2: Start With Bookmarker
decide the length of the the book marker, breadth can modified later also.
decide the material of the book marker, plastic or metal or paper.
metal ones can be made from aluminium beverage can .
I have chosen plastic.
cut the LED strip to the length of the bookmarker.(read the next step before cutting)
cut 2 strips of that length.one for each side of the bookmarker.
Step 3: Flaps
cut 2 strips of cardboard to make flaps that prevent light shining directly to eyes.
stick this flaps to the bookmarker as shown. it should be foldable.
Step 4: Working With LED Strip
most of the LED strips work with 12V power supply , small battery packs don't give 12V so we need to modify the LED strip a bit according to the battery that has to be used.
I have used 3.7v li-ion battery (from old nokia mobile).
LED max voltage is 3.2v (in my case)(in most of the LED strip ,LEDs have max voltage around 3v).
In LED strips ,3 LEDs and a resistor are conected in series , this group is conneced in parallel with other similar groups to form strip.
To run these LEDs with 3.7v battery i have removed all the resistors by desoldering . and connected all the LEDs in parallel .
[if you want to run LEDs in 9v supply replace all resistors with a short (only for LED strip which has 3LEDs in group).]
Step 5: Preparing Battery Holder
i have already used this mobile for some other project .
so remove all apart then , electrically isolate the battery connectors from the mobile circuit.
this can be done by cutting the connections around the connectors using blade( don't cut the board).
draw some wires from the connectors.
i have cut off the unwanted part of the mobile body.
and cut the circuit also . but i haven't bcz it may be useful for other projects.
Step 6: Control Circuit
the 3.7v battery gives around 4v when fully charged , so i have to droped this extra 1v in a resistor. totally two strips of LED consume about 400mA . so r=v/i , r=2.5ohm in my case. i have also added a pot in series to control the brightness of LEDs.(all of them in series with battery and LEDs).
I made a hole in the mobile body to take out the knob of pot.
fit all the components inside and glue it up.
give the potentiometer a knob. by turning the knob the brightness of the LED can be varied .
use pot of 500E or lesser to get good (fine)control.(i have used 1kE which is a little coarse)
if wanted ,take connections for charger pin.
Step 7: Clips
copper wires can be taken from coaxial wire or from inductor coils from scrape circuit boards.
I made some clips attached to the mobile body from copper wires.
Step 8: Attaching to Books
from these clips this unit can be attached to books easily.
Step 9: Stick It
stick the LED strip to the bookmarker.
test it .
it also works with 2 or 3 ,AA or AAA rechargable batteries and 3.7 v battery packs.
Step 10: Connect the Battery to LED Strip and Cut the Book Marker to the Required Breadth .
check out the demo of brightness control video .
Step 11: Add Support for Bookmarker.
the book marker can be used like this or a extra support can be added.
strip a little insulation of the flexible aluminium wire.
insert the aluminium wire into the small compartment of the mobile body through a small hole from the side.
bend aluminium wire for more grip and fill m-seal adhesive (like sugru) and let it dry completely.
punch two holes to the book marker and insert the wire and bend it firmly.
add some m-seal to make it firm if needed.
now the flexible support is ready.
Step 12: This Can Be Used in Many Possitions
Step 13: Watch the Video .
Step 14: This Can Also Be Used As Table Lamp or Can Be Shared
i made this specially for students.