Well here we are nearly 20 years on from the original post and I came looking for the same Jing Neng JN3060F part
Others have suggested a part like this which is widely available from many sources
The 12V Floor or Table light dimmer has an electronic transformer incorporated. It has a 240V mains input and a 12V 60W output. This means you are able to use low voltage halogen lamps. General Characteristics Amperometric protection Protection against transitory surge voltages Self-resetting...
www.mr-resistor.co.uk
Unfortunately the source I purchased if from did not show internal pictures of the units which might have alerted me to the issues
Its certainly is the right item in that it works works correctly
The item I bought is a Relco 5500
Pri : 230/240v
Sec : 12ac 20-60w
BUT
Despite it having a CE mark, I would question the units safety on a couple of points
1. The slot for the slider has no shielding plastic whatsoever (well a small token effort on one side) so that whatever position the black plastic slider is in there in an open view into the unit thru the slot when unit is closed. OK you can't get a finger in, but I can clearly see the windings of the choke near the blue capacitor - i.e. the 240V end of things. and other components.
The original Jing device, while might have been considered cheap junk does at least use a slider design on the case which means there is no open slot for anyone to poke anything in or for anything to drop into at any time
2. The positioning of the terminal blocks relative to the cable clamps makes it very difficult to mount the cable in the terminals correctly
3. The mounting points for the cable clamps are so close to the board that its difficult to properly secure the sheath of the cable in the clamp
So the Jeng part might have been considered cheap junk at the time, but 20 years later it seems they have managed to cut costs even further
Another possible replacement - without the large open slot
The Huibolong HT6024V1 is suitable for all kinds of low voltage halogen floor lamps up to 60w. These are extremely popular sliding foot dimmers that come with a variety of light fittings purchased from large lighting stores. This model has a black casing and is not compatible with LED bulbs...
www.savemylight.co.uk