At 17:23 12/09/99 -0500, you wrote:
>> At 14:58 10/09/99 +0200, you wrote:
>> >I'd like to know how much current can be legally drawn from the CO line
>by a
>> >line-powered device.
>
>> This depends on the counrty that the device is going into. Nominally over
>a
>> 30 minute period the average must be 50uA or less, with short (Very short)
>> spikes of up to 5mA permitted
>
>Off hook, you're only guaranteed 20mA, and at no particular voltage.
>Typically, you get closer to 50-100mA at 4-12V, but it's a pretty fuzzy
>number.
>
>


There is no guarentee on 20mA being the lower limit, this can be offered
over a voltage range from 7.5V to 48V++. Typically exchanges like the
System 12 did have off hook detetion down to 8mA, but this is prone to
problems. Most counties will accept down to 12mA. AS most lines are well
under 4.2kM, the amount of current available at off hook is around 30 tp
50mA. 100mA is not typical as this implies a 200R feed brige, most now have
an upper limit of around 72mA. If your phonw will oeprate down to hook
voltages of 2.5 to 3V then there is no reason why you can not take more
current as possible. You will find that most specs will end at arounf 7.5V
accross the terminals, so theroy says that you may take as you wish under
this votlage limit (Until the terminal vlotage is passed) But this is not
the question it si what can be takne when on hook, and that I have answered

Dennis