Is this what you had in mind?Originally posted by Ahmed@Aug 24 2005, 08:44 AM
I need some tutorial about Telephone circuits
if any body know .......... please help me
thankx for all
My question might be off topic, but satisfy my curiosity: Is that awesome page Dave's work? Dave, AAC administrator?Is this what you had in mind?
Telephone Circuits on Dave's Discover Circuits Website
DC current increases as a result of the drop in impedance. Ohms Law subjected to algebra. Typically, less than 10mA will be drawn with the phone on-hook, and more than 15mA will be drawn with the phone of-hook. At 48Vdc, that means less than 3200 Ohms off-hook versus more than 4800 Ohms on-hook.No.
The CO detects DC current drawn by an off-hook phone then generates the dial tone.
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by Jake Hertz
by Jake Hertz