You always need a transformer to get your lighting system to work. 
This is our 60w transformer that turns the 230V in your wall socket to DIY safe 12V.
LightsOn Garden Plug & Play. A flexible 12-volt lighting system for your garden. 

Easy to install and easy to extend (max 50m) to reach all parts of your garden. 
Designed in Sweden for the tough Nordic climate, all components are made of durable and weather proof materials, 
guaranteeing a long maintenance free life.
Keep it simple! Add a photocell that automatically turn the lights on in the evening and off again at dawn.

Specifications:
• 230 volt -> 12 volt AC 
• 60 watt (60 VA), 51 watt maximum load 
• IP67