I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?

On Feb 17, 8:50*am, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

Check the actual current draw and calculate the time it will buy you.

On 2/17/2011 8:50 AM, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new batteries).
When I have a power failure, the computer keeps right on ticking, but I
always have to restart the DSL modem. I've even restarted the modem
while running on the UPS and after its restart, all was fine. I am
assuming here that the switch over time is killing the modem. I looked
at the modem and its walwart. It says 12 VDC. I was wondering if putting
a few thousand micro farad cap across the 12 volt line might help.
Anyone have any experience with something like this?

The whole point of a UPS is to prevent the very issue you are
describing. There shouldn't be any "switch over time". Sounds like the
UPS has issues.

Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?



The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

On Feb 17, 10:14*am, Tegger wrote:
Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

The cap if it works would be a whole lot cheaper solution. I'm not
familiar with smaller ups' only the big ones. I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. Thus they have to switch
sources.

jamesgangnc wrote in
:

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. Thus they have to switch
sources.




Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in.
The switching time is on the order of milliseconds, short enough that the
gap isn't noticeable to the equipment.

Maybe older UPS's used caps to bridge the gap if the switches were too slow
to be invisible to the equipment. I'm guessing here.


--
Tegger

Art Todesco wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?

I would agree that you probably could use a newer / better UPS with a
faster or no switching time. It is also possible that the DSL modem's
cheap power supply has inadequate filter caps, or they are cheap and
have failed. A new power supply may solve the problem, or adding a big
cap as you indicated should also allow it to ride through a few cycles
of outage while the UPS switches.

On Feb 17, 10:22*am, jamesgangnc wrote:
On Feb 17, 10:14*am, Tegger wrote:





Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

The cap if it works would be a whole lot cheaper solution. *I'm not
familiar with smaller ups' only the big ones. *I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

What you describe is a "true online" UPS and they exist, but generally
cost about 5-10x that of a typical consumer grade "line interactive"
UPS of the same VA rating.

nate

On Feb 17, 10:41*am, Tegger wrote:
jamesgangnc wrote :

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in.
The switching time is on the order of milliseconds, short enough that the
gap isn't noticeable to the equipment.

Maybe older UPS's used caps to bridge the gap if the switches were too slow
to be invisible to the equipment. I'm guessing here.

--
Tegger

You can't use a cap cause how would that work? Caps don't store ac.
The inverter isn't on until it decideds to switch.

On Feb 17, 11:30*am, N8N wrote:
On Feb 17, 10:22*am, jamesgangnc wrote:





On Feb 17, 10:14*am, Tegger wrote:

Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

The cap if it works would be a whole lot cheaper solution. *I'm not
familiar with smaller ups' only the big ones. *I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

What you describe is a "true online" UPS and they exist, but generally
cost about 5-10x that of a typical consumer grade "line interactive"
UPS of the same VA rating.

nate- Hide quoted text -

- Show quoted text -

Yes, I remmeber the first one of those I worked with back in the
80's. Our facility had offices in front and a warehouse in the back.
There was this small room back in the warehouse so we took it over and
put the ups in it. Day one we figured out that it was hot as hell in
that little room. Noisy too. Fortunately it was on an outside wall
so we made a hole inthe wall and added an ac.

On Feb 17, 8:50*am, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

Create your own power failure by unplugging wall, and see if
you have the same result.

greg

On Feb 17, 12:47*pm, zek wrote:
On Feb 17, 8:50*am, Art Todesco wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

Create your own power failure by unplugging wall, and see if
you have the same result.

greg

Clarify, unplug power to UPS for a few seconds.

greg

On Feb 17, 1:05*pm, "A. Baum" wrote:
On Thu, 17 Feb 2011 08:50:59 -0500, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new batteries)..
*When I have a power failure, the computer keeps right on ticking, but I
always have to restart the DSL modem. *I've even restarted the modem
while running on the UPS and after its restart, all was fine. *I am
assuming here that the switch over time is killing the modem. *I looked
at the modem and its walwart. *It says 12 VDC. *I was wondering if
putting a few thousand micro farad cap across the 12 volt line might
help. *Anyone have any experience with something like this?

I'd try a 1.5 farad cap used on auto power amps. Usually can pick one up
for 10+ bucks. That should buffer the source more than enough and would
be much cheaper than a new UPS. *

Seriously, We don't even know the voltage of the supply except its
suppose to be 12 at rated current
output. Its easy to fry something. Unregulated outputs go up over 16
volts.

As I said, pulling the plug on the UPS will narrow down the problem
better.
I'm worrying some other telephone line problem can occur during a
power
failure, up setting the modem. Many devices also warn of reconnecting
a wall-wart supply while still active.

On Thu, 17 Feb 2011 08:50:59 -0500, Art Todesco
wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?
Using a cheap stand-by "almost" power converter?? (that's what APC
stands for)? Many of the cheap standby units have lousy transfer
times. Short of changing UPS units, the large 25 volt capacitor wouls
likely be the most effective solution. Don't whimp out and use a 12
volt. 16 would be OK, but a 25 will last a whole lot longer (you are
looking at unfiltered rectified ac, not clean DC on those power
warts).

On Thu, 17 Feb 2011 07:22:57 -0800 (PST), jamesgangnc
wrote:

On Feb 17, 10:14Â*am, Tegger wrote:
Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). Â*When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. Â*I've even
restarted the modem while running on the UPS and after its restart,
all was fine. Â*I am assuming here that the switch over time is
killing the modem. Â*I looked at the modem and its walwart. Â*It says
12 VDC. Â*I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Â*Anyone have any experience with
something like this?

The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

The cap if it works would be a whole lot cheaper solution. I'm not
familiar with smaller ups' only the big ones. I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. Thus they have to switch
sources.
Even a lot of the "larger" UPS units work that way. There are
"standby" units (the cheap kind with switch-over drop-out), Line
interactive (which switch over very quickly, using zero crossing
switches or similar tech) and there are the genuine on-line, or "dual
conversion" units the have absolutely no change-over or drop-out - and
you pay accordingly.

On Thu, 17 Feb 2011 08:30:52 -0800 (PST), N8N
wrote:

On Feb 17, 10:22Â*am, jamesgangnc wrote:
On Feb 17, 10:14Â*am, Tegger wrote:





Art Todesco wrote in news:ijj941$bqu$1
@speranza.aioe.org:

I have a computer and DSL modem tied to an old UPS (with new
batteries). Â*When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. Â*I've even
restarted the modem while running on the UPS and after its restart,
all was fine. Â*I am assuming here that the switch over time is
killing the modem. Â*I looked at the modem and its walwart. Â*It says
12 VDC. Â*I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Â*Anyone have any experience with
something like this?

The UPS is probably switching in too slowly for the modem's logic
circuitry.

The need to restart the modem is a giveaway that it's losing power for the
tiniest moment, just enough for its logic to /begin/ to die, but not enough
for it to die /all the way/ and thus do a complete reset on the new power-
up.

I think you need a newer UPS.

--
Tegger

The cap if it works would be a whole lot cheaper solution. Â*I'm not
familiar with smaller ups' only the big ones. Â*I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. Â*Thus they have to switch
sources.

What you describe is a "true online" UPS and they exist, but generally
cost about 5-10x that of a typical consumer grade "line interactive"
UPS of the same VA rating.

nate
And a "line interactive" is still head and shoulders above the cheap
old "stand-by" UPS. In old APC parlence there was the cheap "Back-ups"
and the interactive "Smart-ups".

In article ,
wrote:

On Thu, 17 Feb 2011 08:50:59 -0500, Art Todesco
wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?
Using a cheap stand-by "almost" power converter?? (that's what APC
stands for)? Many of the cheap standby units have lousy transfer
times. Short of changing UPS units, the large 25 volt capacitor wouls
likely be the most effective solution. Don't whimp out and use a 12
volt. 16 would be OK, but a 25 will last a whole lot longer (you are
looking at unfiltered rectified ac, not clean DC on those power
warts).

More likely he's looking at a switching power supply in the wall wart.

On 2/17/2011 12:35 PM, jamesgangnc wrote:
On Feb 17, 10:41 am, wrote:
wrote :

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. Thus they have to switch
sources.

Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in.
The switching time is on the order of milliseconds, short enough that the
gap isn't noticeable to the equipment.

Maybe older UPS's used caps to bridge the gap if the switches were too slow
to be invisible to the equipment. I'm guessing here.

--
Tegger

You can't use a cap cause how would that work? Caps don't store ac.
The inverter isn't on until it decideds to switch.

Well, actually, I can, because the wallwart puts out 12VDC and the
cap would be across that 12 volts. I agree with one poster that
measuring the current and then calculate the time gained by a
particular cap. But, I think I found the real reason. I think it's
the ISP.
I'll post more later.

On Feb 17, 12:35*pm, jamesgangnc wrote:
On Feb 17, 10:41*am, Tegger wrote:





jamesgangnc wrote :

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in..
The switching time is on the order of milliseconds, short enough that the
gap isn't noticeable to the equipment.

Maybe older UPS's used caps to bridge the gap if the switches were too slow
to be invisible to the equipment. I'm guessing here.

--
Tegger

You can't use a cap cause how would that work? *Caps don't store ac.
The inverter isn't on until it decideds to switch.- Hide quoted text -

- Show quoted text -

I would work because he's talking about putting the cap across the 12V
DC output of the wallwart that powers the modem. Sounds like a
reasonable
solution to try. On the other hand, I suspect the UPS isn't working
correctly
because the whole purpose of the UPS is to do what it doesn't seem
able to
do.

On Feb 17, 2:05*pm, Smitty Two wrote:
In article ,





wrote:
On Thu, 17 Feb 2011 08:50:59 -0500, Art Todesco
wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?
*Using a cheap stand-by "almost" power converter?? (that's what APC
stands for)? Many of the cheap standby units have lousy transfer
times. Short of changing UPS units, the large 25 volt capacitor wouls
likely be the most effective solution. Don't whimp out and use a 12
volt. 16 would be OK, but a 25 will last a whole lot longer (you are
looking at unfiltered rectified ac, not clean DC on those power
warts).

More likely he's looking at a switching power supply in the wall wart.- Hide quoted text -

- Show quoted text -

I have a few wall warts with switching power supplies but many are
still transformers. It's easy to tell, the ones with switching
circuits instead of transformers are usually lighter and have a higher
current rating. Another giveaway is that many of the switching ones
accept anything from 100vac to 220vac.

On 2/17/2011 8:50 AM, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right on
ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says 12
VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?
Well, I did more testing. I unplugged the UPS and both computer and
modem continued to function properly. So, I tried a bunch of quick
unplug/plugs of the UPS. Everything continued to work. At this
point, I'm tending to blame the ISP. Here's why. Verizon used to
be the provider ... now, it's Frontier. I know, in Verizon days,
last year, that a power outage would kill the telephone service. I
get service from a remote vault about 2 miles down the road. During
a long power/phone outage, I went down to the remote and talked to
the telephone guy that was dispatched to the remote site. He said
that the batteries were junk and Verizon didn't want to spend the
money to replace them because they knew the Frontier sale was just
around the corner. Funny thing, during that long power outage, DSL
still worked. It apparently comes from the same remote site, but
probably uses different batteries or gets its power differently.
Now, I just have to monitor the outages in the future and possibly
report the problems to Frontier. I've heard both good and bad about
Frontier's response to problems.

On Feb 17, 3:08*pm, Art Todesco wrote:
On 2/17/2011 12:35 PM, jamesgangnc wrote:



On Feb 17, 10:41 am, *wrote:
*wrote :

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in.

In article ,
wrote:

On Thu, 17 Feb 2011 11:05:00 -0800, Smitty Two
wrote:

In article ,
wrote:

On Thu, 17 Feb 2011 08:50:59 -0500, Art Todesco
wrote:

I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?
Using a cheap stand-by "almost" power converter?? (that's what APC
stands for)? Many of the cheap standby units have lousy transfer
times. Short of changing UPS units, the large 25 volt capacitor wouls
likely be the most effective solution. Don't whimp out and use a 12
volt. 16 would be OK, but a 25 will last a whole lot longer (you are
looking at unfiltered rectified ac, not clean DC on those power
warts).

More likely he's looking at a switching power supply in the wall wart.

Possibly - but there are a LOT that are non-regulated rectified
transformers - all the regulation is done in the device itself. Using
a 12 volt cap would be borderline, regardless. I would ALWAYS
over-rate by a minimum 25%. (which would be minimum 15 volts - closest
commercial value being 15vdc)

Down here in the U.S., the calendar reads 2011. The old linear wall
warts are all but long gone.

On Feb 17, 9:50*am, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new
batteries). *When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. *I've even
restarted the modem while running on the UPS and after its restart,
all was fine. *I am assuming here that the switch over time is
killing the modem. *I looked at the modem and its walwart. *It says
12 VDC. *I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. *Anyone have any experience with
something like this?

Run your modem directly off the UPS's battery..

Jimmie

Art Todesco wrote:
On 2/17/2011 4:59 PM, HeyBub wrote:
Art Todesco wrote:

Well, actually, I can, because the wallwart puts out 12VDC and the
cap would be across that 12 volts. I agree with one poster that
measuring the current and then calculate the time gained by a
particular cap. But, I think I found the real reason. I think it's
the ISP.
I'll post more later.

The ISP?

How does your ISP know when power goes off at your house?


Well, out here in the country, there are very few feed lines. So,
if I loose power at my house, chances are, the remote switcher will
also loose power. If the batteries are not good, the site will (and
has) go down.

Ah, thanks for explanation! I thought for a moment there you were weird.

Art Todesco wrote:

On 2/17/2011 4:59 PM, HeyBub wrote:
Art Todesco wrote:

Well, actually, I can, because the wallwart puts out 12VDC and the
cap would be across that 12 volts. I agree with one poster that
measuring the current and then calculate the time gained by a
particular cap. But, I think I found the real reason. I think it's
the ISP.
I'll post more later.

The ISP?

How does your ISP know when power goes off at your house?


Well, out here in the country, there are very few feed lines. So,
if I loose power at my house, chances are, the remote switcher will
also loose power. If the batteries are not good, the site will (and
has) go down.

All the telco remote terminals I've seen have a transfer switch and
connection for a generator. The issues are how long with the poorly
maintained batteries last and how quickly will the telco dispatch a
truck with a generator to the site. I've seen a few larger RTs that do
have permanent standby generators, but most do not.

On Feb 17, 5:23*pm, wrote:
On Thu, 17 Feb 2011 09:35:07 -0800 (PST), jamesgangnc





wrote:
On Feb 17, 10:41*am, Tegger wrote:
jamesgangnc wrote :

I assume the smaller
ones keep costs and heat down by not running the power through a power
supply and inverter 100% of the time. *Thus they have to switch
sources.

Correct. They feed line-voltage until that voltage fails to meet certain
pre-defined criteria. At that point the battery/inverter is switched-in.

On 2/18/2011 9:20 AM, Pete C. wrote:

Art Todesco wrote:

On 2/17/2011 4:59 PM, HeyBub wrote:
Art Todesco wrote:

Well, actually, I can, because the wallwart puts out 12VDC and the
cap would be across that 12 volts. I agree with one poster that
measuring the current and then calculate the time gained by a
particular cap. But, I think I found the real reason. I think it's
the ISP.
I'll post more later.

The ISP?

How does your ISP know when power goes off at your house?


Well, out here in the country, there are very few feed lines. So,
if I loose power at my house, chances are, the remote switcher will
also loose power. If the batteries are not good, the site will (and
has) go down.

All the telco remote terminals I've seen have a transfer switch and
connection for a generator. The issues are how long with the poorly
maintained batteries last and how quickly will the telco dispatch a
truck with a generator to the site. I've seen a few larger RTs that do
have permanent standby generators, but most do not.
Yah, under Verizon days, we had a long phone outage on a Friday in
the morning. It went on until about 9:30PM when V brought a
portable generator and restored power. Even after commercial power
was restored the next day, the generator stayed there for about 2
months. I think a big company in the industrial park must have
squawked. Imagine not have phones all day on a Friday, even. I
don't know this for sure, but, I'd bet V left the generator there
until they installed new batteries, just to appease that large
company. Then again, knowing V, they probably just never bothered
to pick it up and bring it to there storage facility!

JIMMIE wrote:
On Feb 17, 9:50 am, Art Todesco wrote:
I have a computer and DSL modem tied to an old UPS (with new
batteries). When I have a power failure, the computer keeps right
on ticking, but I always have to restart the DSL modem. I've even
restarted the modem while running on the UPS and after its restart,
all was fine. I am assuming here that the switch over time is
killing the modem. I looked at the modem and its walwart. It says
12 VDC. I was wondering if putting a few thousand micro farad cap
across the 12 volt line might help. Anyone have any experience with
something like this?

Run your modem directly off the UPS's battery..


I'd think twice before trying that. There's a good chance that the battery
voltage is floating far from ground.