LED is the most interesting part of amateur electronics hobbyist. The main barer of LED is, it needs minimum 3 vlots to illuminate. I’ve found many circuits to drive LED by a single cell alkaline or manganese cell.

This is a complete circuit

This is the coil of my first circuit.

I collected copper wire from a relay and use a plastic-coated paper clip as core.

For Experiment: I use a transformers 12-0-12 part as coil and it worked!

This is the first circuit I made

After making the circuit I wanted to check how long it will work. I found it can illuminate more than one day by a single cell!

The Circuit Diagram

Complete Circuit with ferrite core

Circuit

More Circuit Picture

The Coil

The coil is the important part of the circuit. you can use 20-20 turn to any maximum turns. it will works better with ferrite core but you can use any core. At the first time i used a paper clip as core with 70-70 turns and it worked nicely.