dattier@ddsw1.mcs.com (David Tamkin) (05/27/90)
In volume 10, issue 386, Tad Cook and Julian Macassey both replied to
my earlier questions about ringer equivalency numbers. Below, "DT>"
prefaces what I asked in an earlier submission. My current comments
are flush left.
DT> 1. What does the B or A after an REN mean?
TC> A B type ringer must respond to 16 to 68 Hz ringing frequency, and
TC> an A ringer only responds to 20 or 30 Hz, +/- 3 Hz.
Frequency of what, if I may ask? That question has been slid on past
throughout this discussion under the assumption that everyone must
already know. It certainly isn't the pitch of the ringer's sound, and
it isn't the frequency at which the AC is alternated...or is it?
DT> 2. If the ringer on a telephone can be turned off, does it no longer
DT> count in figuring the total REN load on a line?
TC> A phone with the ringer turned off SHOULD have no REN load on the
TC> line, but I could imagine an electronic ringer that still has its
TC> detector across the line, but the sound source is off.
So the REN has nothing to do with powering the ringer so much as with
recognizing *whether* to sound the ringer?
DT> 3. Two of my modems *do* have REN's, though neither has any sort of
DT> bell or gong. They check in at "0.4 1.2B" and "0.5A 1.6B"
DT> respectively. My other modem has a speaker and thus does make a noise
DT> (but the speaker is powered by the electric utility, not the telco);
DT> it has an FCC ID but no REN on it at all.
TC> What's the question?
Good point; I realized that myself after rereading my own words in the
Digest. Somebody had said that yes, there could be 0 REN's: look at a
modem or an answering machine for examples. So I looked at my modem
and at my answering machine (which reads 0.4 B) and said, gee, hey,
these numbers are not zero.
Those were Cook; these are Macassey:
DT> 1. What does the B or A after an REN mean?
JM> I think I covered this in an earlier posting, but then I could have
JM> glossed over it.
Maybe you did, but when you and the other techie types in this Digest
write at each other's level, my eyes (and the eyes of other readers)
glaze over and roll backwards. You could put "the surf was great off
Los Angeles today" into the middle and most of us wouldn't be able to
read through the technical stuff to find that. Yes, this digest-cum-
noozgroop is the place to discuss the technical end as well as the
user's end, but please understand that a non-techie reader like me can
miss something written deep inside an incomprehensible submission
about the specifics of the guts of wires and switches.
If it's any consolation, if you did cover that in another posting, you
probably explained it in a way I couldn't have understood if I had
read it, so I'd have had to ask again regardless.
JM> See an earlier posting of mine where I waffle about this.
I can't read your crackers, let alone your waffles. If you ever post
a brioche, I won't even try.
DT> 2. If the ringer on a telephone can be turned off, does it no longer
DT> count in figuring the total REN load on a line?
JM> [Essentially, Macassey's reply was that if you shut off the ringer
JM> switch on the outside of the telephone, no, but if you open the
JM> phone up and disconnect the wiring to the entire ringing circuit
JM> (not just the part that makes the noise), yes. At least I guess
JM> that's what he was trying to say.]
All I know is this: if the phones whose ringers I have shut off do
count toward the allowed REN total, it beats the heck out of me how
the remaining ones still ring loud enough to wake me up when my mother
decides to play alarm clock. ("This is your mother, David," she
records on my answering machine as if I couldn't recognize her voice.
"I know it's early, but" she's decided to phone me anyway, almost
always about something that could have gone unsaid altogether.)
DT> 3. [See quote of my #3 above if you want to reread it.]
JM> ... In truth, all modems I have seen are type B ringers. To prove
JM> this, feed say 60V at 60 Hz (yes power via a regular transformer)
JM> to a modem; betya it picks up if in answer mode.
May those among the readership who do not own the equipment to feed
voltage X at frequency Y into the inwards of appliance Z nor the tools
and know-how to fix the damage afterward be excused from this project,
please? "Betya" you didn't know there were any of us here.
JM> I wrote extensively about all this ringer stuff years ago in Popular
JM> Communications mag, but I suppose it wasn't all that popular then.
JM> Plus of course the editors used to bugger and censor my text so some
JM> of the more esoteric stuff was jumbled and meaningless by the time it
JM> reached the public and vulgar gaze.
The editors didn't have to do that. The esoteric stuff is already
meaningless to the public gaze without their help. All you experts,
please be tolerant if we ask for a re-explanation of something in more
common terms or if we don't realize that a question is equivalent to
one posed previously in thick jargon.
David Tamkin Box 7002 Des Plaines IL 60018-7002 708 518 6769 312 693 0591
MCI Mail: 426-1818 GEnie: D.W.TAMKIN CIS: 73720,1570 dattier@ddsw1.mcs.comjulian@bongo.uucp (Julian Macassey) (05/28/90)
In article <8316@accuvax.nwu.edu>, dattier@ddsw1.mcs.com (David Tamkin) writes: > In volume 10, issue 386, Tad Cook and Julian Macassey both replied to > my earlier questions about ringer equivalency numbers. Below, "DT>" > prefaces what I asked in an earlier submission. My current comments > are flush left. > DT> 1. What does the B or A after an REN mean? > TC> A B type ringer must respond to 16 to 68 Hz ringing frequency, and > TC> an A ringer only responds to 20 or 30 Hz, +/- 3 Hz. > Frequency of what, if I may ask? That question has been slid on past > throughout this discussion under the assumption that everyone must > already know. It certainly isn't the pitch of the ringer's sound, and > it isn't the frequency at which the AC is alternated...or is it? This is the frequency of the AC ringing voltage. The standard ringing signal is a voltage between 40 and 150 Volts at 20 Hz. The ringer has a capacitor between it and the phone line. This cap blocks DC voltage so it doesn't ring when the normal 48V DC line voltage is on the line. The capacitor (0.47 uF for Gong ringers, 1 uF for electronic ringers usually) passes AC blocks DC. Yes, I know gong ringers will not ring when DC voltage is applied across them, they will just consume power relative to their DC resistance. But electronic ringers will warble merrily with DC across them. So yes, the Hz thing is the frequency at which the AC is alternated. > DT> 2. If the ringer on a telephone can be turned off, does it no longer > DT> count in figuring the total REN load on a line? > recognizing *whether* to sound the ringer? As I have stated before, the REN is a measure of the power consumed by the ringer. Tad Cook was not really correct in stating that turning the ringer off removes the load. As a rule, it doesn't, it just silences the transducer. In a gong ringer, it merely mechanically stills the clapper. This means that power is being consumed. My previous posting rambled on this at some length. A ringer is not a "logic" device, it doesn't make decisions, it is like a light bulb. Light bulbs consume power, a 100 Watt bulb uses half the power of a 200 Watt lighbulb. A circuit can only tolerate so many watts (usually stated in Amps because the Voltage is known). Put too many light bulbs on a circuit and you blow a breaker. If you used a small generator or battery and put too many light bulbs on the circuit, they would get dimmer if you added too many. If you put enough on, they would lower the voltage so much that they would cease to glow, although collectively they would consume all the power the gerator could put out. With the Electrical grid pumping out megawatts it takes special circumstances to cause these "brownouts". Alas, the ringing generator at the phone company is five Watts or so and over five ringers is liable to cause a brownout. > Good point; I realized that myself after rereading my own words in the > Digest. Somebody had said that yes, there could be 0 REN's: look at a > modem or an answering machine for examples. So I looked at my modem > and at my answering machine (which reads 0.4 B) and said, gee, hey, > these numbers are not zero. Yes, as I said before, if it consumes less than 0.1 REN it is registered as 0.0. To know that a line is ringing and pick up a line as a modem, phone answering machine, voice mail system would do, you just need to detect that old AC voltage. You do not need to consume the voltage to drive relays etc, you can use the electrical company to do that. But many modems and answering machines consume ringing power to drive circuitry, some even use a ringer chip and then use the rectified output of the ringer chip to drive logic. A KISS approach that uses power. You don't have to do it this way, but it is neat and simple. Also most modems are the only device on the line so the power consumption is not important. Answering machines on the other hand almost always share the line with other devices - yes phones with real ringers - so can often be the straw that breaks the camels back. Often the first device to malfunction when too many ringers get on the line is the phone answering machine. I have found that Panasonic answering machines, despite all the wonderful things I say about them, to be the most sensitive to ringing voltage. Yes, as you add ringers (RENs) to the line, the ringing voltage will drop. > DT> 1. What does the B or A after an REN mean? > JM> I think I covered this in an earlier posting, but then I could have > JM> glossed over it. > Maybe you did, but when you and the other techie types in this Digest > write at each other's level, my eyes (and the eyes of other readers) > glaze over and roll backwards. You could put "the surf was great off > Los Angeles today" into the middle and most of us wouldn't be able to > read through the technical stuff to find that. Yes, this digest-cum- > noozgroop is the place to discuss the technical end as well as the > user's end, but please understand that a non-techie reader like me can > miss something written deep inside an incomprehensible submission > about the specifics of the guts of wires and switches. I have done my best to explain this stuff to the non technical. But I assume that if someone wants to know how a ringer works that they do understand Ohms law and a few basics. To explain it to my mother, I would just say, ringers use power just like light bulbs and you cant have too many. When you turn off a ringer, you don't switch it off like a light bulb, you just mute it's output, like putting a black bag over a light bulb. But then I assume my mother doesn't read this stuff. She doesn't think I understand any of it anyhow. My neighbour says that Malibu had radical waves this morning. > If it's any consolation, if you did cover that in another posting, you > probably explained it in a way I couldn't have understood if I had > read it, so I'd have had to ask again regardless. > DT> 2. If the ringer on a telephone can be turned off, does it no longer > DT> count in figuring the total REN load on a line? > JM> [Essentially, Macassey's reply was that if you shut off the ringer > JM> switch on the outside of the telephone, no, but if you open the > JM> phone up and disconnect the wiring to the entire ringing circuit > JM> (not just the part that makes the noise), yes. At least I guess > JM> that's what he was trying to say.] Yes, he is saying exactly that. See my "mother explanation" above. > All I know is this: if the phones whose ringers I have shut off do > count toward the allowed REN total, it beats the heck out of me how > the remaining ones still ring loud enough to wake me up when my mother > decides to play alarm clock. Well if you have five REN 1 ringers and they all ring when "on" and you shut off four then the remaining on ringer will ring. The other four are still consuming power, but you can't hear them. Just like black bags over light bulbs, you can't see the light, but you are still consuming power. So of course the remaining ones will still ring loud enough. Why shouldn't they? They did before you turned some off, but the load on the line is the same. > JM> ... In truth, all modems I have seen are type B ringers. To prove > JM> this, feed say 60V at 60 Hz (yes power via a regular transformer) > JM> to a modem; betya it picks up if in answer mode. > May those among the readership who do not own the equipment to feed > voltage X at frequency Y into the inwards of appliance Z nor the tools > and know-how to fix the damage afterward be excused from this project, > please? "Betya" you didn't know there were any of us here. Ok, so I mentioned the simplest, cheapest, easiest way to test a ringer. Use a regular Rat Shack power transformer. This is so if anyone who want's to mess with wires to prove or disprove what I say can do it. If anyone really wants to know more etc, they can always mail me, phone me or even take me out to eat in a really sleezy and disreputable joint and pick my brains. It is not my intent to obfuscate this stuff, I leave that to professionals - the writers of computer manuals (-: Julian Macassey, n6are julian@bongo.info.com ucla-an!denwa!bongo!julian N6ARE@K6IYK (Packet Radio) n6are.ampr.org [44.16.0.81] voice (213) 653-4495