I've got this light made up of little LEDs. I intend to use it for a DIY ring light but the issue is that it works on AC only. I tried using a 12v DC power source but it didn't work at all. I've tried bypassing the AC circuit all together and connecting 5v DC power directly to the LEDs, but only groups of 5 LEDs light up very dimly. What do I do please to make the whole thing run at full brightness with DC

 

Welcome to AAC!

What you're observing doesn't make sense. If the light requires AC, some LEDs should light with DC. Have you tried reversing the polarity of DC to see if it gives different results?

It would be helpful if you make a schematic for the light so we know what you're working with.

 

You can employ a variety of techniques to convert AC to DC. In you opening sentence you have a device that works on AC only. I think you should start there and help us figure out how you can obtain the proper AC voltage for your device.

 

What AC voltage are you using to power the little LEDs?? and how many of them are there?? None of the explanation in the post #1 makes any sense at all, and so I know that a lot of information is missing. Is the string of LEDs wired in parallel? or in series?r is the TS unable to answer that question,.
What is totally clear is that we are not given the right information.

 

So you have lights that work on AC but not DC. And you want to know how to covert AC to DC. Why? So the lights don’t work?

 

We KNOW that LEDs do not work directly on ac , And from that we can conclude that we are not given all of the information. What is missing is any information about whatever it is that is directly connected to the LEDs.
So I am waiting for the TS to describe what it is that is connected between the AC suplied and the actual LEDs.

 

I've got this light made up of little LEDs. I intend to use it for a DIY ring light but the issue is that it works on AC only. I tried using a 12v DC power source but it didn't work at all. I've tried bypassing the AC circuit all together and connecting 5v DC power directly to the LEDs, but only groups of 5 LEDs light up very dimly. What do I do please to make the whole thing run at full brightness with DC

There may be a capacitor at the input and that makes DC input ineffective.
Can you post some pictures and a schematic of the circuit if possible?

 

Certainly there is a big part of the assembly that we are not given any information about: " I've tried bypassing the AC circuit all together and connecting 5v DC power directly to the LEDs, "

So that portion is some sort of power converter circuit that supplies some unknown voltage to an unknown number of LEDs.
So the TS wants us to suggest a solution to a problem without any clues presented.