A killer project if u ask me(literally)- Gave me quite a few 230v shocks while debugging but finally it works.
This is my first project working with ac mains.I tried the same project earlier with a hand wound transformer ,with magnet wire wound on a ferrite rod but it gave flickering results.Hence the toroidal transforrmer.The system produces a mild hum but a sturdy box enclosure might help nullify it.Cool project to have when the neighbourhood power station is down or just to install in your backyard.
Schematic Source :Electronics for You Magazine
Transformer: Toroidal Type 5A, 12-0-12,230V
Battery : 7.5AH SLA maintanence free
Check out the pic for scematic, working and all info you need !
Here are MY TIPS if u decide to build one yourself:
1.Don't keep the secoundary open while testing.It can go to a lethal 1000V.
2.Use high wattage resistors if u have them.
3.I melted my breadbord prototyping it.My suggestion is to build it dirctly on pcb- incase you wish to build it.I've already tested its validity:-)
4.I used a toroidal transformer.Use them to have better performance.
5.When testing the device try to use low wattage cfl first.Immediately switch off device if cfl flickers.It implies wrong connections in circuit.
In conclusuion, I would say it is a cool project to try if you want to learn about working with AC.