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Picture of Quick and simple LED mason jar
Mason jars and leds are almost made for eachother. They are eye appealing and just plain fun. I am going to show you how to make a very simple one that involves a few cheap componets you can find anywhere online! This could be considered an introductory project for those new to electronics but why set limits? You like it you make it :)  lets get started and embark on the simplicity!

This LED mason jar turns on by itself at night. 



 
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Step 1: Things needed

Picture of things needed
You are going to need;

One mason jar
One 5mm led (color of your choice)
One 3volt button battery
One LDR
One 82k resistor
One 2n3904 switching transistor
Some wire
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TOOLS

Soldering iron
Hot glue gun
Helping hands 
Wire strippers/cutters
Pliers

Step 2: Schematic(s)

Picture of Schematic(s)
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I have included two schematics. One is the, I guess, offical schematic and one is a 'birds eye' view. The second one is intended to give you the feeling as if you were looking down at the circuit. I mainly included this for the NPN because I know that they can be tricky if you're new to them. I remember when I first saw one (roughly 6 years ago) I got the pins mixed up all the time and doing so can result in the transistor getting really hot or breaking or even both. 

(three pins are collector, emitter and pin.)

Step 3: The NPN

Picture of The NPN
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I will be walking you through how to make this small circuit without using a PCB (printed circuit board). Now if you want to use a PCB go right ahead and do so :) I figured it would be fun to do without. 

First you're goint to take your pliers and bend the left leg and right leg as shown in the picture. Then tin all three legs. 

Bending them this way ensures no shorts.
Inst11445 months ago

Whats the point of the NPN? If the LDR is a switch couldn't the NPN be eliminated?

Inst11445 months ago

Whats the point of the NPN? If the LDR is a switch couldn't the NPN be eliminated?

Inst11445 months ago

Whats the point of the NPN? If the LDR is a switch couldn't the NPN be eliminated?

lpinho11 months ago

Already bought the components but they forgot to send the LDR :(. Gonna make one with a switch to test light intensity.

These will be my kids night light :)

Thanks