At 14:09 10/09/99 -0500, you wrote:
>Hi,
>
>It seems to me there is no limit to what current you can draw while
>off-hook except that the current is limited by the CO, 26mA is a minimum
>available at 6V.  On-hook is a different story where the limit is very low,
>1uA except while ringing and then ?
>
>(numbers from The Art of Electronics, Horowitz & Hill. 60 US$ you'll never
>regret spending)
>
>Jim Hartmann
>
>


These numbers are wrong, or the interpretation is. The amount of current
avaliable when off hook is dependant on the SLIC providing the line power.
On a PABX the current limites are very different (24V system) to those
provided by a CO, also a CO may provide 50V or 100V battery feed. If you
have alook you will see that most phones will hold down to around 8V
accross the line. The line current at this point can vary greatly! The only
thing that you can assume is that 12mA (Nominal minimum value) is requried
to keep the phone off hook. The current could be upt to 70mA if you are
located cloase to an exchange.

While ringing is another story!


Dennis