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From: julian%bongo.UUCP@nosc.mil (Julian Macassey)
Newsgroups: comp.dcom.telecom
Subject: Re: Ring Voltage in Asia Countries
Message-ID: <16379@accuvax.nwu.edu>
Date: 25 Jan 91 05:17:40 GMT
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In article <16306@accuvax.nwu.edu>, joseph@milton.u.washington.edu
(Joseph Chan) writes:

> I understand that the ring voltage is not internationally
> standardized. 

	The ringing voltage on telephone lines varies between 150 and 40 
Volts. The voltage depends upon, the local standard ringing voltage at 
the CO, the length of the loop (phone line) between the CO and the 
subscriber, the current pulled by the ringer (called REN in the US) 
and lastly the number of ringers attached to the line. So, you can 
consider that the standard voltage is about 90-100 Volts. What does 
vary is the frequency of the voltage. 

In the the U.S. the frequency is usually 20 Hz, it can be other
frequencies. In other parts it is often 50 Hz.  So, briefly, a gong
(bell) type ringer from the U.S. may not work in other countries
because they are picky about the ringing frequency. Cheap and sleezy
gong ringers will ring with any type of AC applied. Also "warble"
ringers, the ones that sound like sick birds or crickets in heat are
usually "FCC Type B" ringers and will respond to frequencies between
15 and 68 Hz - the truth is they will respond up to a 150Hz most of
the time.  So, a warble ringer should work anywhere.

> My specific question is that what is the phone line
> voltage provided by each Asia countries? (I am interested to find out
> the phone line voltage for Hong Kong and Indonesia). 

I thought the specific question was ringing voltage, now it is line
voltage. OK, I'll play along. Hong Kong is mostly UK gear so the line
voltage will be around 50 - 52 Volts. I am not familiar with
Indonesia, but you will find that the line voltage for most of the
world is 48V, give or take a few. The exception being Western Germany
which is 60V. Some parts of Italy used to be 60V too. The Phillipines
have a ton of Seimens gear, so they may be 60V.

	But in short, assuming the dialing system of the phone/fax is
compatible be it pulse or DTMF, and assuming the ringer is a class B,
it will work anywhere in the world.


Julian Macassey, n6are  julian@bongo.info.com  ucla-an!denwa!bongo!julian
N6ARE@N6YN (Packet Radio) n6are.ampr.org [44.16.0.81] voice (213) 653-4495