From: usenet@andyburns.uk   
      
   Mike Scott wrote:   
      
   > The relays are switching DC at 12V, but the polarity is determined   
   > before the on/off relay. Most SS relays I've seen are triac-based for AC   
   > only; one type would do DC, but not with the polarity changing (and at   
   > 10x the cost anyway!).   
      
   You could use a H-bridge, rather than build it from discrete   
   transistors/FETs they come as a single or dual bridge in an IC, possibly   
   with built-in snubber network.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)