From: farberbear.unspam@aol.com   
      
   On 8/19/2022 9:08 PM, Phil Allison wrote:   
   >   David Farber wrote:   
   > =============   
   >   
   >> This Schumacher 1042A-PE battery charger stopped functioning today. It   
   >> seemed to work for a little while but when I noticed the car battery's   
   >> voltage wasn't slowly increasing after performing a 2 amp charge for 2   
   >> hours, I checked the voltage at the charger's cables and it was 0 volts.   
   >> The continuity of the switches and cables were all good. I did find a   
   >> power semiconductor which I could not identify, BTW70-200SN. I looked in   
   >> an old ECG cross-reference book and the closest match was for a   
   >> BTW69-800 which is an SCR in a TO-218 package. The package seems to   
   >> match the device I'm looking for. I made some measurements with my   
   >> Simpson 464 DVM on the 2k ohm scale. Pins 1 and 3 measure 38 ohms   
   >> regardless of test lead polarity. All other combinations of continuity   
   >> measure open circuit. In circuit, pins 1 and 2 are soldered together.   
   >> Any idea what this component is or how to test it?   
   >>   
   >   
   > ** Could be an SCR maybe.............   
   >   
   > With a 1A, current limited,  DC supply of about 12 V, + on the anode - on   
   the cathode, apply a brief pulse of +50mA at +1.5V to the gate with - on the   
   cathode as well.  The 12 volt supply should the be clamped at about +1.2V.   
   > You 38 ohm readings are normal.   
   >   
   >   
   > .....  Phil   
   >   
   >   
   >   
   >   
   Hi Phil,   
      
   Looks like I have to make another correction. Jeff pointed out the model   
   number I posted was wrong, the correct model is 1052A-PE   
      
   The other correction is that pins 1 and 2 of the "SCR" are NOT soldered   
   together on the pc board. Pin 2 (center pin) is snipped off and the   
   connection is made through the component's heat sink. This is the same   
   heat sink which is electrically common to one end of four discreet   
   (bridge?) diodes.   
      
   Getting back to the testing of the SCR (if it is an SCR), how do I   
   identify anode, cathode, and gate?   
      
   Thanks for your reply.   
   --   
   David Farber   
   Los Osos, CA   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)