They are on Amazon too, but here is one I found. You just want to make sure your not taxing the converter for your low voltage lights. If you only have one or two lights you should be fine, if you have 15 of them you would need to look into it a little further.
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F382602462335