What would you like to learn?!!!!!!!
- Thread starter mingez
- Start date
TwistedCU
New member
Nick, I'm not sure where you got your info on telephone lines, but ...
A telephone line is 48V DC, but when it rings, it is 48V AC, not 90-120V - which would fry a ringer set. You are correct that it is normally not 60 hz, but the actual frequency varies between different types of switching and central office equipment.
A solid short circuit would quickly fry an OE port in a central office. It is all electronic these days and the line will shut down automatically within a few seconds. The power supply for plain old telephone service is still a large bank of big 48V batteries in vaults underneath the C.O.'s.
A telephone line with a DSL still runs on 48V dc. A T1 or any other high-capacitance circuit can run at voltages substantially higher then 60 volts, in many cases more than twice that amount and can be quite deadly.
The threshold for high/low voltage is 60 volts - at least as the federal government sees it from a safety standpoint. That is the minimum voltage that can throw a heart into fibrillation (as I mentioned above). That is why OSHA requires CPR/first aid for those employees. I am sure that in any given field that deals with electricity, their view of what high and low voltage varies but it is 60V as the feds see it.
I have on many occasions worked in the wet weather and got into ringing voltage . It hurts and will leave burn marks on the skin. It's not lethal, but as I stated above it will give you a little respect for low voltages and it'll definately get your attention.
Trust me I am sure about this stuff. It is what I do. I didn't want to get into an electrical pissing match with ya, I just wanted to point out that low voltages are often underestimated. I hate to see it talked about so casually, as these welders have the power to melt metal.
On a side note, if anyone has ever seen the result of a set of auto jumper cables hooked up backwards it can give you an idea what merely 12V is capable of when there is alot of current present. Do you not have a warning label in your 12V electric vehicle?????
A telephone line is 48V DC, but when it rings, it is 48V AC, not 90-120V - which would fry a ringer set. You are correct that it is normally not 60 hz, but the actual frequency varies between different types of switching and central office equipment.
A solid short circuit would quickly fry an OE port in a central office. It is all electronic these days and the line will shut down automatically within a few seconds. The power supply for plain old telephone service is still a large bank of big 48V batteries in vaults underneath the C.O.'s.
A telephone line with a DSL still runs on 48V dc. A T1 or any other high-capacitance circuit can run at voltages substantially higher then 60 volts, in many cases more than twice that amount and can be quite deadly.
The threshold for high/low voltage is 60 volts - at least as the federal government sees it from a safety standpoint. That is the minimum voltage that can throw a heart into fibrillation (as I mentioned above). That is why OSHA requires CPR/first aid for those employees. I am sure that in any given field that deals with electricity, their view of what high and low voltage varies but it is 60V as the feds see it.
I have on many occasions worked in the wet weather and got into ringing voltage . It hurts and will leave burn marks on the skin. It's not lethal, but as I stated above it will give you a little respect for low voltages and it'll definately get your attention.
Trust me I am sure about this stuff. It is what I do. I didn't want to get into an electrical pissing match with ya, I just wanted to point out that low voltages are often underestimated. I hate to see it talked about so casually, as these welders have the power to melt metal.
On a side note, if anyone has ever seen the result of a set of auto jumper cables hooked up backwards it can give you an idea what merely 12V is capable of when there is alot of current present. Do you not have a warning label in your 12V electric vehicle?????
RE: sm420
Hi,
These are quotes from multiple web sites I found after doing a yahoo search:
-Nick :!:
Hi,
These are quotes from multiple web sites I found after doing a yahoo search:
According to these sources, ring voltage *could* be as low as 40 volts, but I still believe it to be much higher, as the other sources indicate. Not only do I believe this because have built my own ringer circuit before, in which I had to use above 60 volts, but I also bought an actual telco ring generator which I found surplus. It has clearly marked outputs which say "Output: 90-120 VAC, 30Hz" I have used this ring generator on many phones, and there have been no problems.TwistedCopper said:
Then the current is limited...TwistedCopper said:
Yes, it does vary. I believe the auto industry considers anything above 50 volts as high-voltage.TwistedCopper said:
Are you sure it was only 48 volts? Burn marks and such would make me think it was a higher voltage that got you...TwistedCopper said:
No pissing here. However, I'm going to do a bit more research on this now, as you've made me curious....TwistedCopper said:
Are you referring to car batteries potentially exploding due to seeing reverse current? If so, that kind of result could occur on a battery of any voltage. Batteries don't much like it.TwistedCopper said:
-Nick :!:
TwistedCU
New member
window zipper problem
If you are in Texas, you are probably in old GTE territory (now Verizon). I am not sure if the network is the same there as the former Bell Atlantic area (now also Verizon) that I work in, but I would assume they are very similar if not the same.
You do understand where I was going when I asked about you having a warning label on your electric Jeep, right? All I'm saying is low voltage can be hazardous. It is not always, and rarely the case, but it can be.
XJNick said:
If you are in Texas, you are probably in old GTE territory (now Verizon). I am not sure if the network is the same there as the former Bell Atlantic area (now also Verizon) that I work in, but I would assume they are very similar if not the same.
You do understand where I was going when I asked about you having a warning label on your electric Jeep, right? All I'm saying is low voltage can be hazardous. It is not always, and rarely the case, but it can be.
TwistedCU
New member
One other thing, the info you got from ATT is referring to an old electric-mechanical switch type system. There were several different types of switching equipment and hardly any of them are used today. Most lines work on technology like Starspan, Lightspan 2000, SLIC-96, and newer electronic office equipment (a 5E switch for example) that uses inter-office multiplexers instead of copper trunk cables to communicate between them.
RE: Re: Here are some progress pics
Hi,
The ring generator I bought doesn't appear to be very old at all. I don't know when it was made, though. I'm not disputing that you work with telco stuff everyday. I believe you. However, I've found that the ring signal here is different from what you posted (see below)
I did measure the ring voltage and frequency with a good multimeter just a few minutes ago. I saw between 88 and 92 volts AC at 24.5 Hz coming across the line during ringing. This was of course with the multimeter on the AC scale. I checked the line with the meter on DC (when all phones were on hook), and saw 51.4 volts DC. So you are correct, the normal voltage is about a 48 volt system. Note, that the 51.4 volt DC signal was STILL PRESENT on the line while the ring signal was on the line. This makes perfect sense if the AC voltage is superimposed over the DC voltage as the internet sources I read stated. So yes, there is about a 48 volt DC voltage on the line during ringing. but, there is also around a 90 volt AC signal present, and THAT is the one that will certainly shock you.
Oh, and I don't need to be electrocuted to sense the voltage. That is what multimeters are for.
And yes, I certainly believe you when you say that it hurts. 
I'm not here to try to prove you wrong. I believe you if you say that a 50 volt AC ring signal is what you see on phone lines in your area. I'm just pointing out that I see 90 volts AC during a ring signal on my phone line, and that also happens to be what my ring generator produces. I too am sure that TelCo signals vary by region. The above info is simply based on what I see here (in central Texas).
Yes, and I do have warning labels. Though, I wouldn't classify my Jeep as being low voltage. It is 160 volts DC... :mrgreen:
However, you bring up a good point. Low voltage can be dangerous. High voltage can be dangerous. Electricity in general can be dangerous. It is all about using the right tools, using common sense, and not working with power systems that you are not familiar/ comfortable with. This is why I find it annoying when people say that electric vehicles are more dangerous than gas-powered vehicles due to the higher voltage....
-Nick :!:
Hi,
TwistedCopper said:
The ring generator I bought doesn't appear to be very old at all. I don't know when it was made, though. I'm not disputing that you work with telco stuff everyday. I believe you. However, I've found that the ring signal here is different from what you posted (see below)
TwistedCopper said:
I did measure the ring voltage and frequency with a good multimeter just a few minutes ago. I saw between 88 and 92 volts AC at 24.5 Hz coming across the line during ringing. This was of course with the multimeter on the AC scale. I checked the line with the meter on DC (when all phones were on hook), and saw 51.4 volts DC. So you are correct, the normal voltage is about a 48 volt system. Note, that the 51.4 volt DC signal was STILL PRESENT on the line while the ring signal was on the line. This makes perfect sense if the AC voltage is superimposed over the DC voltage as the internet sources I read stated. So yes, there is about a 48 volt DC voltage on the line during ringing. but, there is also around a 90 volt AC signal present, and THAT is the one that will certainly shock you.
Oh, and I don't need to be electrocuted to sense the voltage. That is what multimeters are for.
And yes, I certainly believe you when you say that it hurts. I'm not here to try to prove you wrong. I believe you if you say that a 50 volt AC ring signal is what you see on phone lines in your area. I'm just pointing out that I see 90 volts AC during a ring signal on my phone line, and that also happens to be what my ring generator produces. I too am sure that TelCo signals vary by region. The above info is simply based on what I see here (in central Texas).
TwistedCopper said:
Yes, and I do have warning labels. Though, I wouldn't classify my Jeep as being low voltage. It is 160 volts DC... :mrgreen:
However, you bring up a good point. Low voltage can be dangerous. High voltage can be dangerous. Electricity in general can be dangerous. It is all about using the right tools, using common sense, and not working with power systems that you are not familiar/ comfortable with. This is why I find it annoying when people say that electric vehicles are more dangerous than gas-powered vehicles due to the higher voltage....
-Nick :!:
TwistedCU
New member
RE: Selling the Jeep (ouch)
Just for kicks I just tested mine. 46V AC ringing voltage (I didn't bother testing frequency). I was already aware that the DC voltage remains on the line while it rings, and it is one of the only examples of the two types of voltage being run on the same circuit of anything I have ever dealt with. I never would have thought that possible before working for the phone company.
I guess the telco equipment varies more than I thought. I figured yours would have been closer to 50V. I wonder why that system uses a higher voltage, as I don't start to troubleshoot a line unless it drops below 40VAC.
Good to know though, and it'll have me picking the brain of a couple of the old-timers at my work location
As for your Jeep being 160V, I'm going to quit while I'm behind but I'm glad we agree on the safety issue. I felt the need to state it when I got a mental image of some welder-to-be checking to see if he could really shock himself harmlessly :lol:
Just for kicks I just tested mine. 46V AC ringing voltage (I didn't bother testing frequency). I was already aware that the DC voltage remains on the line while it rings, and it is one of the only examples of the two types of voltage being run on the same circuit of anything I have ever dealt with. I never would have thought that possible before working for the phone company.
I guess the telco equipment varies more than I thought. I figured yours would have been closer to 50V. I wonder why that system uses a higher voltage, as I don't start to troubleshoot a line unless it drops below 40VAC.
Good to know though, and it'll have me picking the brain of a couple of the old-timers at my work location
As for your Jeep being 160V, I'm going to quit while I'm behind
but I'm glad we agree on the safety issue. I felt the need to state it when I got a mental image of some welder-to-be checking to see if he could really shock himself harmlessly :lol:is there anywhere like this on the east coast.
I was welding something ( dont remember what) the garage floor was damp.
Hot outside maybe 80-90 and like 60 in the garage. So the floor starts to condensate.
Anyway, I was using a Lincoln Arc (set about 120 amps) and was Shocked across my back ( I was on my back under the car i think.) I remember it feeling like needles.
I was welding something ( dont remember what) the garage floor was damp.
Hot outside maybe 80-90 and like 60 in the garage. So the floor starts to condensate.
Anyway, I was using a Lincoln Arc (set about 120 amps) and was Shocked across my back ( I was on my back under the car i think.) I remember it feeling like needles.
Inspector-Gadget
New member
RE: My Jeep
mud4feet wrote:
G-G-G-G-g-g-g-g-r-r-r-r-o-o-o-o-o-a-a-a-a-n-n-n-n-!-!-!
HAHAHAHA!!!!
Okay…while we wait for Nick and Twisted to sort out the scintillating details of their rather shocking discussion…:wink:
(Twisted and Nick are both correct. Telephone signaling techniques have evolved over decades. It depends on the system in question and where and how voltages and currents were measured in that system.)
POP-QUIZ
Can any of our techies name this bird?
(The answer is given below, but you will have to turn your monitor upside-down to read it.)
(You should hum the "Jeopardy" tune while pondering your answer.)
+
+
+
+
+
+
+
+
+
+
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Regards,
Gadget
PS: Yes, I do know that I have way too much time on my hands.
mud4feet wrote:
G-G-G-G-g-g-g-g-r-r-r-r-o-o-o-o-o-a-a-a-a-n-n-n-n-!-!-!
HAHAHAHA!!!!
Okay…while we wait for Nick and Twisted to sort out the scintillating details of their rather shocking discussion…:wink:
(Twisted and Nick are both correct. Telephone signaling techniques have evolved over decades. It depends on the system in question and where and how voltages and currents were measured in that system.)
POP-QUIZ
Can any of our techies name this bird?
(The answer is given below, but you will have to turn your monitor upside-down to read it.)
(You should hum the "Jeopardy" tune while pondering your answer.)
+
+
+
+
+
+
+
+
+
+
+
Regards,
Gadget
PS: Yes, I do know that I have way too much time on my hands.
currupt4130
VT Hokie
thread officially high jacked by nick and TC
currupt4130
VT Hokie
95 Full Size Bronco rear end in TJ
hehe i dont care i was just stating the obvious
hehe i dont care i was just stating the obvious
mud4feet
New member
RE: jeep clubs
There is no such thing as irrelevant information - especially the information you provide here on Jeepz, Nick, that all of us get to suck in for free!!! (and you, too, Twisted). What I would like to learn (the subject of this thread) is everything that I don't know already (or have forgotten.....I'm an old fart, remember?). Unfortunately, don't have enough years left or brain capacity remaining to accomplish that, so I'll settle for learning how to weld and suckin' in all the electrical knowledge I can from my learned Jeepz brethren!!! Oh, almost forgot.........and learnin' the right lines that'll get me and my little "sissy" :lol: stocker TJ up the mountain to where I want to go without invoking the "Winch" command!!
XJNick said:
There is no such thing as irrelevant information - especially the information you provide here on Jeepz, Nick, that all of us get to suck in for free!!! (and you, too, Twisted). What I would like to learn (the subject of this thread) is everything that I don't know already (or have forgotten.....I'm an old fart, remember?). Unfortunately, don't have enough years left or brain capacity remaining to accomplish that, so I'll settle for learning how to weld and suckin' in all the electrical knowledge I can from my learned Jeepz brethren!!! Oh, almost forgot.........and learnin' the right lines that'll get me and my little "sissy" :lol: stocker TJ up the mountain to where I want to go without invoking the "Winch" command!!
TwistedCU
New member
I was trying to think up another, but I came up short
Rather shocking don't you think?
I think we have run the circuit on this hi-jack, and although I hate to impede it, because it has been a nice break from debates on current events
I just thought adding a little spark to this thread might be good, I didn't want anyone to blow a fuse :?
Rather shocking don't you think?
I think we have run the circuit on this hi-jack, and although I hate to impede it, because it has been a nice break from debates on current events
I just thought adding a little spark to this thread might be good, I didn't want anyone to blow a fuse :?
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