INTL 3:770/1 3:770/3   
   REPLYADDR bp@www.zefox.net   
   REPLYTO 3:770/3.0 UUCP   
   MSGID:  5d752537   
   REPLY:  609bfbf3   
   PID: SoupGate-Win32 v1.05   
   bp@www.zefox.net wrote:   
   > side, you could put it all downstream of the Pi power supply   
   > and skip line detection entirely. That's a big advantage.   
   >   
   On second thought, this is probably wrong. If one connects   
   to a Pi a 5 volt supply in parallel with a blocking diode   
   and a 6 volt battery, the diode is still forward biased   
   and will drain the battery eventually. Some kind of switch   
   is needed, controlled by line detection.   
      
   Maybe a three terminal regulator set for 5 volts out powered   
   by a 9 (or higher) volt battery pack could be substituted.   
   Still, one has to consider the idle draw of the regulator.   
   TI's LM340 takes 6 mA roughly. Still, that's a smallish   
   supply for a Pi. You'll likely want something larger.   
      
   Apologies for the red herring!   
      
   bob prohaska   
      
   --- SoupGate-Win32 v1.05   
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)   
   SEEN-BY: 10/0 1 15/0 90/1 103/705 105/81 106/201 128/260 129/305 135/225   
   SEEN-BY: 153/757 7715 218/0 1 601 700 840 870 930 220/70 221/1 6 226/17   
   SEEN-BY: 226/30 100 227/114 229/110 111 112 113 200 206 307 317 400   
   SEEN-BY: 229/426 428 470 550 616 664 700 240/1120 266/512 267/800   
   SEEN-BY: 282/1038 291/111 292/854 301/1 113 812 310/31 320/219 322/757   
   SEEN-BY: 335/364 341/66 342/200 396/45 460/58 633/280 712/848 770/1   
   SEEN-BY: 770/3 100 330 340 772/210 220 230 5020/400 1042 5058/104   
   SEEN-BY: 5075/35   
   PATH: 770/3 1 218/840 221/6 301/1 218/700 229/426