This LED flasher circuit will run for 10 years on a single 1.5v AA alkaline cell.

I have also included a PC-board. You can download it in PDF format here: PCB download . You will also find a component placement guide. Such long cell life is achieved by limiting average current drain to an initial value of 50uA(0.05mA) .

Step 1: PC-board and Component Placement Guide

DOWNLOAD LINK to PC-board and component placement guide.

I made this prototype using the Heatless (cold) toner transfer method

Step 2: Circuit Diagram & Component List

IC1: CD4001 (cmos quad NOR gates)

Q1: 2N4401 (NPN transistor)

C1: 100nF (0.1uF) ceramic capacitor

C2: 1nF (0.001uF) ceramic capacitor

C3: 10uF x 12v tantalum capacitor

R1: 4M7 resistor

R2: 2M2 resistor

R3: 4k7 resistor

LED: ultra-high efficiency LED (available current is very low)

T: 1/2" toroidal ferrite core & 2 meters (6 ft) of 24AWG (0.5 mm) enameled wire

BAT: 1.5 alkaline AA cell. (battery holder optional)

Step 3: Circuit Operation Details

Step 4: Making the Transformer

You can salvage the ferrite core from an old PC motherboard or power supply. Polarity of windings is important; if LED doesn't light when shorting header pins invert one of the windings.