XPost: comp.sci.electronics, rec.electronics, sci.electronics   
   From: Howard@Fcc1.biz   
      
   I asume you know how to make the relay driver. Just trigger it with a   
   555 Integrated Circuit available at any radio shack. Try google for   
   applications of 555 IC Timers. Its just a matter of adjusting the RC   
   value on the timer.   
      
   Howard Epstein   
      
   Peter Hucker wrote:   
   > I need to make a relay switch on 1 second after a 12VDC line comes on, but   
   switch off immediately the 12VDC goes off.  What's the best way to do this?    
   If you need to know why I want this, see the paragraph below:   
   >   
   > I have a solar power setup and wish to switch the load between the invertor   
   output and the mains supply.  Currently I have a relay with a 240VAC coil   
   which does the switching based on the output of the invertor.  It doesn't work   
   too good - the invertor    
   output falls a bit as the battery gets low, and the relay starts jumping back   
   and forth.  What I would prefer is to use the 12V signal from the solar   
   regulator (which is on whenever the battery is ok (and is what switches the   
   invertor on).  However I    
   need to wait at least 1 second before moving the load to the invertor, as the   
   invertor takes a while to start up.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)