wrote:

I have a couple of "sealed" devices that apparently have negative temp coefficient devices inside of them that are placed between a power outlet and the lights. The lights start out at 1/3 normal brightness and come up to full level in 5-10 seconds. Soft turn-on means less light failures. I would like to have/make several of these, but I don't know what is inside the boxes and don't really feel like tearing them apart if I don't have to.


** The devices are probably "NTC thermistors".

http://www.ampron.com/UploadFiles/Ot...0338_50489.jpg

They come in a range of sizes and resistance values.

You need to measure the cold resistance value to establish the latter.

Last time I needed some, I found them on Ebay from dealers in HK.

.... Phil