XPost: alt.home.repair, sci.electronics.repair   
   From: occassionally-confused@nospam.co.uk   
      
   MightyWannabe wrote:   
      
   > There is a good possibility the rectifiers (diodes) in your alternator   
   > could fry because it is recommended that your car be running when you   
   > jump start another car. The rectifiers of your car is supplying electric   
   > current from the alternator and can overload due to the jump start   
   > operation.   
      
   In the recipient car, when the engine finally starts, I was told since I   
   was young that the best way to "absorb" some of the excess current in the   
   first few seconds is for the recipient to turn on the headlights.   
      
   This seems counterintuitive from the recipient's standpoint in terms of   
   "using" current but the theory is that the "B" sense circuit of the   
   alternator (which is just a coil of wire in the end) senses a "very low"   
   battery so it tells the alternator to put out a "very high" current, whose   
   initial burst could ("they say") fry the rectifying wheatstone diodes.   
      
   Maybe it makes sense to the electronics folks who are asked to comment.   
      
   > There is also the possibility of the voltage drop so low momentarily   
   > that your car stereo's anti-theft system kicks in, and you'll have to go   
   > back to the car dealership to enter the anti-theft code. The anti-theft   
   > system detects the zero voltage when it is ripped from the dashboard.   
      
   But what happens each time you replace the battery every few years?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)