I have 8 12V,20W bulbs and want to connect them in series. I cant seem to find a 12V,160W transformer for my 240V mains supply. Is there another way like connecting in series+parallel connection to use them directly with 240V mains? Any suggestion is welcome...
12V bulbs and the lamps in which you use them are in general NOT designed to be run directly off the mains voltage. They are designed to run with a transformer which provides mains isolation.
I would advise you to get not one but several transformers like 2 times 80 W or 4 transformers of 40 W.
Also 20W bulbs are very oldfashioned, why not get some LED lights instead, for the same amount of light you would only need one 30 W transformer.