Picture of Simple USB Led light
usb led sema.png
usb sema za 3 led.png
i dont want to speak much i will just show you how to make.
first you will need is solder iron and solder ofc. then you need 3 white led (its about 5 cents each=15 cents , it depends where you buy, i bought it in Serbia and here is 10 cents per one)<, then you need resistors for led  i used 82 ohm resistor ( in serbia its 10 for 9 cents, 110=1 $) and  you need usb cable from old computer or phone.
1st. step is to cut off one end of usb
2nd,  then you solder LED to resistor ( end of one resistor to cathode of led, shorter leg) then you solder other end of resisotor to black (or blue in my case) and anode (longer) of led to red wire on usb
repeat this step 2 more times ( or 10,20 , depends how much led you want)  and you done it.
also i used my cell phone wall charger , you can use it as standard lamp, and  you can design housing,.....

P.S. sorry for bad english, english is not my first language.

i forget, next i will show you how to do electrolysis
tealk (author) 1 year ago
thank you for comnent
tealk (author) 1 year ago
i will put diagram, and every led have its own resistor
Phil B1 year ago
Your English is absolutely fine. Perhaps you could include a circuit diagram. I think I saw five diodes. What is their forward voltage and current draw? Are they in parallel? Is there an 82 ohm resistor on each LED?

Thank you.