From: pcdhSpamMeSenseless@electrooptical.net   
      
   Christopher Howard  wrote:   
   > Hi, I was wondering what is the cheapest (and hopefully, simple to wire   
   > up) way to get an analog square function. I.e., input a voltage x, and   
   > get voltage x^2 out. Or x^2/10. Or some reasonable approximation of   
   > either of those.   
   >   
   > The standard trick is to feed the voltage into both inputs of a   
   > multiplier chip. But even those AD633 chips are tough to afford on my   
   > budget (around 20 USD each).   
   >   
      
   If you want to do analog computing, you’re pretty well stuck with   
   multipliers or log/antilog chips.   
      
   If you’re trying to linearize a control loop, you can play pretty fast and   
   loose with discrete BJTs, because that doesn’t need high accuracy, and the   
   loop will track out the offsets.   
      
   Cheers   
      
   Phil Hobbs   
      
   --   
   Dr Philip C D Hobbs  Principal Consultant  ElectroOptical Innovations LLC /   
   Hobbs ElectroOptics  Optics, Electro-optics, Photonics, Analog Electronics   
      
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