USBfying an Automatic Dustbin

ok so this is my first ever instructables ,

so what I am doing today is basically turning my automatic dustbin from AA battery type to li ion charging type

the reason being I don't want to keep buying those AA cells as after a point of time you will realize that you have spent a lot on them.

OR

you can take this project as a tool for reducing the 4.2 max voltage of a li ion/polymer cell to 3v or in that range # *WITHOUT USING A BUCK CONVERTER*

with the help of this you can convert those 2s AA cell holders with li ion rechargeable packs

SO HERE ARE THE TOOLS -

1) A type C TP4056 module to safely charge the single 1s li ion/ polymer cell

2) a li ion cell (obviously)

3) a rocker switch

4) the important component - a diode , this is used to create a 0.7 v drop as a normal diode has a 0.7 voltage drop across it, so basically we are using this disadvantage to our advantage this will step down the voltage from max 4.2 to 3.5 (4.2 - 0.7= 3.5).

5) and some wires

so to get a clear picture ,I opened up the battery compartment where I found the holders to be arranged in a series connection that was a 2s connection ( 2 cells in series)

thus the nominal voltage of a normal AA dry cell is 1.5 volts thus 2 of them is series with create a total of 3volts (1.5+1.5=3.0)

thus conclusion Vin (voltage input ) should be 3v * a bit up and down is fine

so here is the circuit we have a TP 4056 module wired up to a lithium polymer cell

connect the battery's anode to B+

connect the battery's cathode to B-

now connect the OUT + AND OUT - TERMINALS

on the OUT + terminal connect a diode and a rocker switch both in series

# FOLLOW THE GIVEN DIAGRAM #

so now the circuit is complete so wire it up to the main output of the dustbin the positive and the negative terminals take care of polarity as we are working with direct current.

so now time to assemble everything back

drill a hole on the lid , in my case I made a elliptical hole by using heat I basically melted that part of plastic

Caution - mount it somewhere where it doesn't block the movement of the lid and while mounting everything fix everything firmly as the USB socket will go through a lot plug in an out so it has to be mounted firmly hot glue is recommended

after this paint the surrounding area of the hole to give it a finish in my case putting some black tapes did the job.

so place the switch in such a place where it is easily available in my case I hid it on the inside of the previous holder ,in the photos you can see how the USB port is connected in my case I cant use it while on charging as it will obstruct the path of opening and closing of lid

but you can solve this if you play around with the positioning of the USB socket.

so its completely on you creative brain how you do it.

at last insulate every joint with insulating tape to avoid short circuits

so if even you are fed up with chaing you AA cells you might want to do this project

so hope you liked it this was a very simple project and i wish you luck if you try making one

have a wonderful day.