Introduction: DIY Simple Solar Lamp
Lets make a simple solar lamp for nameplates,etc
We will make a very simple circuit using a single NPN transistor
You can replace any components with alternatives
You can design and print the casing the way you like.
Supplies
You will need the following:
SL100 transistor
Solar panel 5V
18650 Liion Cells
LDR and 4.7k pot
1W Leds
Capacitors and resistors
Optional:
3d printer
Nut and bolts
Step 1: Circuit Diagram
This is the basic circuit diagram
The resistor value will adjust your output current for led hence brightness
Pot will adjust the sensitivity to sunlight
IMPORTANT
I used a simple voltage step down to get a constant voltage of 4.2v for charging
and used a big battery as buffer against over charge and over discharge
It is recommended to use a BMS for avoiding these issues
Step 2: Design and Print Casing for Your Lamp
I used Fusion 360 and Ender3 V2
You can use anything as per convenience
Step 3: Installing Electronics and Assembling
I made the circuit on a small perf board for convenience
Roughly pasted everything using feviquick and fevicol
Make sure to test everything before installing
For attaching the cover I pasted the nuts of in the corners and installed using the bolts
from outside

