Post by thread:[EE]:Ac Signals I Think This Should Be simple? Nee

Hello All, I have a signal that is composed of the following: It is a 30Hz Signal at 38 Volts A.C that is Interrupted every 2 Seconds like a Ringing Signal on a Telephone but has no D.C component involved. This signal does ring a telephone. Here is my Problem. When the above signal is ringing the phone the voltage across the phone is measured during the ring cycle at 38 volts A.C, when the phone is taken off hook the voltage drops to 7.2 volts A.C. What I need to do is detect this drop or off-hook condition and reset the Pic processor in my design. The problem I see is that I only want to reset the processor when the phone is taken off hook and not during the non-ringing cycles and also how to actually convert the voltage drop into a usable logic level for a Pic reset. Therefore 30 Hz @ 38.0v A.C with 2 sec Interruptions = On Hook No reset 30 Hz @ 7.20v A.C with 2 sec Interruptions = Off Hook Reset Pic I know I can detect an off hook on a regular telephone line but this circuit has no dc component involved to use for this detection. Does anyone have any ideas for a simple way to do this simple reset? Regards, Steve. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Hi, What do you want to do when the ring signal is not present (on hook or off)? Regards, Dave Steve Kasm wrote: > 30 Hz @ 38.0v A.C with 2 sec Interruptions = On Hook No reset > > 30 Hz @ 7.20v A.C with 2 sec Interruptions = Off Hook Reset Pic -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu