What's this?

[relikya]

Hi community;

I am working with a flame detector head, and its PCB comes with an integrated which seems to be a transisor (i.e. 2n2222) but this device has two pins only.

Its name is:

506
C212AH

I've been told this device may be a quick switching diode. I am not sure.

Does anyone know this device?

Thx

 

[relikya]

here the pics community;

http://a.imageshack.us/img824/643/c212ah3.jpg
http://a.imageshack.us/img839/8904/c212ah1.jpg
http://a.imageshack.us/img823/5968/c212ah2.jpg

this element is between +VCC and zener diode. The zener is acting as power supply.

thx