[Waverley ARS] Wyong Field Day - Scroungers Corner (vola)

[Eddie Hanham]

   For those that were at Wyong on the weekend and picked up a 13.8 power
   supply that was cactus, here is some hope.

   I got two for $10 expecting if I couldn't repair them I could  use the
   case as a housing for other projects.

   I checked the two P/S 240ac circuit at the plug and found them open
   circuit.

   Checked the fuse and mains swith and they were ok so removed the
   transformer.

   Knowing it was cactus I decided to check the red mains winding on the
   transformer by removing the plastic tape. I did this because most
   breakages occur near the connection to the plastic insulated wire.
   Imbedded under the insul;ation tape was a thermal switch which, when
   checked, was O/C. It was an AUCA 115 deg C 5 amp 10mm square plastic
   device.

   I have looked on the internet and in retail store catalogues but can't
   find an AUCA supplier in country.

   Found the following site though:

   http://www.uchobby.com/index.php/2007/03/20/wall-wart-scrounging/

   Which describes same details of finding the device.

   Anyone help in finding replacement AUCA square device. Jaycar have a
   tublular ones which evidently don't give the same heat transfer.

   Haven't checked the rest of the Power supplies but suspect the 2N3055
   pass transistors failed and overheated the TX. the 2n3055 transistors
   don't have .1ohm restors and evidently if one goes the lot go!!

   BUT THERE's MORE

   Seeing I found the above site there are more articles on the same site
   that may be of interest to others, check out other side bar articles
   under SCROUNGING.

   This one helps identify components:

   http://www.uchobby.com/index.php/2007/07/15/identifying-electronic-comp
   onents/

   Any comments

   Eddie

   VK2BEH