In this article I have explained regarding how to connect and illuminate a few 5mm LEDs using a 3.7V Li-Ion cell, normally used in cell phones. I keep receiving requests from the readers who seem confused with the connection details of 5mm LEds with a 3.7V Li-ion cell. The requests inspired me to write this […]
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LED Flashlight Circuit using 1.5 V Cell
This LED flashlight circuit is able to power a Luxeon type LED with a single 1.5 V battery. This results in a miniature flashlight that will not run out quickly. By: P. Martin Basically it is a boost converter circuit which boosts the 1.5 V DC from a AAA cell and converts it into a […]
Digital Thermometer Circuit – Uses a Solar Cell for Power
The articles explains a digital thermometer circuit project that works without a battery. Instead of a battery the circuit utilizes a small solar cell and operates by deriving power from the ambient light available from the surrounding light sources. This allows the circuit to be extremely compact, light weight, versatile and hassle free while measuring […]
6 Useful DC Cell phone Charger Circuits Explained
A DC cell phone or mobile phone charger is a device which charges a cellphone from an available DC supply source. The device converts the unregulated DC source into a constant current and constant voltage output which becomes safe for any mobile phone charging. In this article I have explained how to build DC to […]
How to Illuminate 1 Watt LEDs with Cell Phone Charger
Nowadays probably all of us have a spare cell phone charger lying idle in our cupboards or table drawers……so wouldn’t it be a great idea if we could employ it like a super bright 1 watt LED driver and illuminate our room with white cool moon light. Circuit Concept As we all know that a 1 watt […]
Cell Phone Emergency Charger Pack using Ni-Cd Batteries
In this post I have explained the construction of a simple emergency charger pack using Nicket Cadmium (Ni-Cd) batteries for your cellphones and smart phones for emergency charging of your cellphone, so that next time you are never stuck on a highway with a full discharged dead cellphone battery. Circuit Concept It often happens, our […]





