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- Newsgroups: sci.electronics
- Path: sparky!uunet!caen!mtu.edu!cmwolf
- From: cmwolf@mtu.edu (christopher m. wolf)
- Subject: Re: telephone ringer voltage
- Message-ID: <1993Jan6.183924.14172@mtu.edu>
- Organization: Michigan Technological University
- References: <jecome01.726341429@starbase.spd.louisville.edu>
- Date: Wed, 6 Jan 1993 18:39:24 GMT
- Lines: 28
-
- jecome01@vulcan.spd.louisville.edu (Eric Comer) writes:
- >I was wondering if anyone knew the voltage that is sent on the ringer
- >line of a telephone cable when a call is incoming. any help would be
- >greatly appreciated.
- >
- (extracted from a lengthier document)
- ...
- You should conform to the following:
-
- TYPE MIN (Ohm) NOM. (Ohm) MAX. (Ohm)
- ==================== ========= ========= =========
- *******************************Impedance**********************************
- --------------------------------RINGING-----------------------------------
- AC (at 40Hz, T=R) 1,000
- AC (680 Hz to 1660 Hz) 2,000
- ...
- The Phone Company will provide you:
-
- TYPE MIN NOM. MAX.
- ==================== ========= ========= =========
- Voltage DC (T=R) 47 V 48 V 105 V
- Ring AC voltage (T=R) 40 Vrms 90 Vrms 130 Vrms
- Ring frequency 15.8 Hz 20 Hz 68 Hz
- Ring ON/OFF time 1s/1s
- DC current 20mA 30mA 120mA
- Noise 15dBrnC
- ...
- T=R means tip to ring
-