If you’re like me and started out the hobby on a budget you probably ended up buying cheap 100-LED Chinese 240V LED strings from ebay or similar.
These strings typically have the 8 function control box and plug directly into the 240VAC (or 110VAC) mains socket.
The problems with using these strings are numerous.
Firstly the LEDs run on rectified 240V AC. This means that there is the potential for someone to be killed, or worse, if they come into contact with any bare wires.
These strings are generally used outdoors and of course 240V and water don’t mix. I cut off the 8 function control boxes and connected the strings to a rectified 240V output on my SSR, but if you use the control box, they are not waterproof and often very flimsy. You definitely don’t want to get water into there!
I had some LED strings that were probably 110V DC and the resistors ran quite hot. One or two strings actually smoked and I had to disconnect the string for fear of fire.
Finally there is a lot of power being wasted in those series resistors and this could be put to better use (eg more lights).
The attached PDF shows the method I use to convert 240V strings to 24V.
As with anything electrical you perform the processes described at your own risk. Furthermore the user should check the accuracy of any and all information before it is relied upon and I take no responsiblity for the accuracy of the information I provide or the way in which it is used.