[GreenKeys] Loop Supply

[UEOGUY]

Wow!  That was the logic behind the "black box", which allowed conversation to a called number, between the ring cycles, by making the connection, without tripping the ring!   The good old days when they had Phone Police!  And every phone savvy person would disconnect the ringers in phone so they could have extra extensions!  I always wondered how they current limited a single phone line.  I've seen the Submarine cell batteries used, the solid copper buss bars,  the rotary DC generators, and solid state rectifiers used in the old No.5 XBAR central offices to charge the batteries, I guess it was those ballast tubes, that limited the current in the line relays.  Wonder what they use now?
Bob

----- Original Message ----
From: Larry Tighe <larryradio at worldnet.att.net>
To: Bob Camp <ham at cq.nu>
Cc: greenkeys at mailman.qth.net
Sent: Tuesday, March 11, 2008 7:20:17 PM
Subject: Re: [GreenKeys] Loop Supply

Did  ya  know,  there's  a  law  against  using  the  current  from  a  phone  line  to 
charge  batteries???   I  guess  somewhere  along  the  "line",  telco  figured  out 
folks  were  charging  by  avoiding  "picking"  the  L  or  line  relay.....just 
enough  current  to  trickle  the  batteries  but  not  pick  the  L  relay  and  bring 
up  "supervision".

Telco  did  supply  DC  on  a  seperate  pair  for  charging  batteries,  ringing 
voltage  too,  for  small  PBX's.

I  have  other  important  things  to  tell  like  the  above....but  enuf  for  now!

lar

Sent:  Tuesday,  March  11,  2008  18:24
Subject:  Re:  [GreenKeys]  Loop  Supply


>  Hi
>
>  So  what's  the  matter  with  the  "normal"   approach.  100  wet  cell  nicads 
>  wired  in  series?
>
>  Float  charge  them  in  banks  off  of  the  phone  line  ....
>
>  Bob
>
>
>  On  Mar  11,  2008,  at  12:39  PM,  Larry  Tighe  wrote:
>
>>  Enough  already  of  this  technical  discussion  on  loop  supplies!
>>
>>  I  think  I'll  simply  plug  a  bridge  rectifier  into  my  AC  socket.   A   nice 
>>  100  watt  lite  bulb  can  limit  the  current  for  my  magnets.
>>
>>  Then,  put  the  TTY  machines  on  old  wooden  skids.   The  radio  gear  is   even 
>>  simpler,,,,just  cut  off  the  ground  pin  on  the  plugs.
>>
>>  Simply  jump  up  on  the  wooden  skids  so  your  not  grounded  and  wah  lah, 
>>  you're  on  the  air.
>>
>>  Phooey  on  transformers....they're  for  beginners!
>>
>>  lar
>>  K2JIA

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