From: bill.sloman@ieee.org   
      
   On 6/03/2026 4:12 am, Christopher Howard wrote:   
   >>   
   >> parallel protection1    parallel protection2   
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   > Thank you, would you mind please explaining a little more about these   
   > parallel protection circuits, i.e., how the protection works?   
      
   It's depressingly simple-minded. The current through a silicon diode is   
   an exponential function of the current though it.   
      
   https://en.wikipedia.org/wiki/Shockley_diode_equation   
      
   typically 0.6V of voltage drop  gets you about 10mA of current. Add   
   another 60mV and you get ten times as much current.   
      
   Stick two strings of diodes in parallel with your load, one string to   
   limit the positive voltage swings and the other to limit the negative   
   voltage swings, and if you apply an over-high voltage, the bulk of the   
   current flows through the diodes rather than the load.   
      
   Get the data sheet for whatever diode you use and you can work out the   
   rough numbers. Most diodes aren't all that tightly specified, but some   
   are, and if you insist on using cheap diodes at least fix on a single   
   part number and measure what they actually do. It is temperature   
   dependent, but nothing all that dramatic.   
      
   --   
   Bill Sloman, Sydney   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)