View Single Post
  #10   Report Post  
Posted to sci.electronics.repair
John-Del[_2_] John-Del[_2_] is offline
external usenet poster
 
Posts: 446
Default Help Silicon Rectifier

On Monday, April 30, 2018 at 1:40:48 PM UTC-4, Ivan Vegvary wrote:
On Monday, April 30, 2018 at 10:23:34 AM UTC-7, Sjouke Burry wrote:
On 30-4-2018 8:41, Ivan Vegvary wrote:
Fixing old car battery charger. Do not want to buy new one because I need the 6 volt capability for my vintage motorcycle.

Need to replace a "button style" (Motorola MR2506) rectifier with a "stud mounted" one (Motorola 1N1190A) The stud mounted on has a higher rating.
Question: Data sheet says button battery cathode marked by "dot". Dot no longer visible on installed parts. Is it safe to assume that the wires from the transformer secondary lead to the Anode and the body of the "button style" (cathode) is pressed into the aluminum plate?
Thank you for your help.

Just put it in, and then load the charger with a 12 volt headlight.
Then check polarity, and flip the rectifier connections if the polarity
is wrong.


Thanks all !!! Problem solved.
Disconnected good diode from circuit, tested and determined that the anode is connected to the transformer and the cathode is pressed on to the metal plate. Will order the 1N1190A stud bolt replacement. Inexpensive, probably less than the shipping cost.
Thanks again !



Just make sure the diode you get is polarized the same. IIRC, those stud rectifiers were available with reverse polarity if ordered that way. Who knows if any of those made their way to the secondary parts market.