Re: [time-nuts] Oncore battery

[Chris Albertson]

I used a non-recharable coin battery and after maybe 5 years it's
still working.  The coin battery will last as long as whatever its
shelf life is.  It is only used if power fails and then only to hold
the data in the volatile memory.


On Mon, Apr 25, 2016 at 3:25 AM, Azelio Boriani
 wrote:
> Panasonic ML621 or equivalent. Alternatively you can use the battery
> pin (pin 6): remove the onboard battery and use en external primary
> cell (CR2032 or equivalent). See pages 15 to 21 of the M12M user
> manual.
> 
>
> On Mon, Apr 25, 2016 at 2:11 AM, Joseph Gray  wrote:
>> Can anyone recommend a rechargeable lithium coin cell that is a direct
>> replacement for the ones that come on some Oncore receivers? Something
>> I can order from Mouser or Digikey, if possible.
>>
>> Joe Gray
>> W5JG
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery

[Clint Jay]

Very handy,  I've picked up a few Oncore receivers recently and was
planning to test them all and then replace the batteries in the good
ones.  Has anyone worked out what the original charge circuit schematic is
though?
On 25 Apr 2016 13:01, "Pete Stephenson"  wrote:

> I have several 5V Oncore UT+ receivers of the type that did not
> include a rechargeable on-board battery, but didn't want to bother
> with lithium primary batteries or rechargeable batteries and their
> associated holders so I opted to use supercapacitors. Specifically, I
> use the Panasonic EEC-F5R5U105 supercap with a capacitance of 1F and a
> max voltage rating of 5.5V.
>
> Charging is easy: I simply run 5V power through a diode and a resistor
> sized to prevent exceeding the diode's current limit and the capacitor
> charges in about 20-30 minutes. The diode prevents the supercap from
> discharging through the resistor when the power fails.
>
> I use a 1N4148 small signal diode rather than a 1N400x-series diode
> because the 1N4148 has a smaller reverse leakage current. A 240 ohm
> resistor keeps the peak current to 20mA (the diode can handle up to
> 200mA forward current) and the capacitor is charged up in about 20
> minutes after power-on. Adjust the values for your specific needs.
> Once charged, it maintains the Oncore's RAM for several weeks with no
> power.
>
> On Mon, Apr 25, 2016 at 12:25 PM, Azelio Boriani
>  wrote:
> > Panasonic ML621 or equivalent. Alternatively you can use the battery
> > pin (pin 6): remove the onboard battery and use en external primary
> > cell (CR2032 or equivalent). See pages 15 to 21 of the M12M user
> > manual.
> > <
> http://www.ilotus.com.sg/~ilotus/sites/all/themes/zeropoint/pdf/m12m/M12M%20-%20User%20Guide%20%28Ver%201.0.0%29.pdf
> >
> >
> > On Mon, Apr 25, 2016 at 2:11 AM, Joseph Gray  wrote:
> >> Can anyone recommend a rechargeable lithium coin cell that is a direct
> >> replacement for the ones that come on some Oncore receivers? Something
> >> I can order from Mouser or Digikey, if possible.
> >>
> >> Joe Gray
> >> W5JG
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
>
>
> --
> Pete Stephenson
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery

[Pete Stephenson]

I have several 5V Oncore UT+ receivers of the type that did not
include a rechargeable on-board battery, but didn't want to bother
with lithium primary batteries or rechargeable batteries and their
associated holders so I opted to use supercapacitors. Specifically, I
use the Panasonic EEC-F5R5U105 supercap with a capacitance of 1F and a
max voltage rating of 5.5V.

Charging is easy: I simply run 5V power through a diode and a resistor
sized to prevent exceeding the diode's current limit and the capacitor
charges in about 20-30 minutes. The diode prevents the supercap from
discharging through the resistor when the power fails.

I use a 1N4148 small signal diode rather than a 1N400x-series diode
because the 1N4148 has a smaller reverse leakage current. A 240 ohm
resistor keeps the peak current to 20mA (the diode can handle up to
200mA forward current) and the capacitor is charged up in about 20
minutes after power-on. Adjust the values for your specific needs.
Once charged, it maintains the Oncore's RAM for several weeks with no
power.

On Mon, Apr 25, 2016 at 12:25 PM, Azelio Boriani
 wrote:
> Panasonic ML621 or equivalent. Alternatively you can use the battery
> pin (pin 6): remove the onboard battery and use en external primary
> cell (CR2032 or equivalent). See pages 15 to 21 of the M12M user
> manual.
> 
>
> On Mon, Apr 25, 2016 at 2:11 AM, Joseph Gray  wrote:
>> Can anyone recommend a rechargeable lithium coin cell that is a direct
>> replacement for the ones that come on some Oncore receivers? Something
>> I can order from Mouser or Digikey, if possible.
>>
>> Joe Gray
>> W5JG
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



-- 
Pete Stephenson
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery

[Azelio Boriani]

Panasonic ML621 or equivalent. Alternatively you can use the battery
pin (pin 6): remove the onboard battery and use en external primary
cell (CR2032 or equivalent). See pages 15 to 21 of the M12M user
manual.


On Mon, Apr 25, 2016 at 2:11 AM, Joseph Gray  wrote:
> Can anyone recommend a rechargeable lithium coin cell that is a direct
> replacement for the ones that come on some Oncore receivers? Something
> I can order from Mouser or Digikey, if possible.
>
> Joe Gray
> W5JG
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Jim Lux]

On 4/6/11 9:00 AM, Joseph Gray wrote:

Recently, the local area had an extended power outage. I have the
Z3801A on a UPS, but the outage lasted over an hour and the UPS
didn't. I have the information about adding a battery to the Oncore to
allow for faster startup. Is it safe to use a supercap instead of a
battery?


Isn't your real problem going to be that the oven on the oscillator has 
cooled off?  Or does the GPS lose the whole almanac, so the time to 
first fix is forever?


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Joseph Gray]

 Isn't your real problem going to be that the oven on the oscillator has
 cooled off?  Or does the GPS lose the whole almanac, so the time to first
 fix is forever?

Yes, the Oncore looses the almanac.

Joe Gray
W5JG

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

This will be interesting.
I have not added a battery to my 3801. Have the same issue annoying but in
general not enough to get me to do something.

But believe it may be as simple as taking a cr3026 lithium as an example and
holder.
Slap it on the back and change the battery every so often. Doing something
with recharge-ables and super caps adds a lot of complexity. Using the
disposable battery should make this a ground and battery connection. Do not
believe a diode is required.
But this approach only works if the almanac memory and such draws very very
low current. Might guess in the 1-10 ua. If its a pig you could always use 2
AA alkalines.
Regards
Paul
WB8TSL


On Wed, Apr 6, 2011 at 12:19 PM, Joseph Gray jg...@zianet.com wrote:

  Isn't your real problem going to be that the oven on the oscillator has
  cooled off?  Or does the GPS lose the whole almanac, so the time to first
  fix is forever?

 Yes, the Oncore looses the almanac.

 Joe Gray
 W5JG

 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Chris Albertson]

On Wed, Apr 6, 2011 at 9:00 AM, Joseph Gray jg...@zianet.com wrote:
 Recently, the local area had an extended power outage. I have the
 Z3801A on a UPS, but the outage lasted over an hour and the UPS
 didn't. I have the information about adding a battery to the Oncore to
 allow for faster startup. Is it safe to use a supercap instead of a
 battery?

I have an Oncore too.  I added a coin size battery salvaged from an
old PC.  It is easy enough to do there is a header pin just for that
purpose.  The Motorola user manual says the battery woks better
because it lasts longer but that was written ten years ago.   If you
use a cap you will want to add a resistor in series to limit current.

The Onore looses the almanac and all settings if there is no battery.
There is zero non-volatile memory in the device.


-- 
=
Chris Albertson
Redondo Beach, California

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

My 2 cents is that a UPS is very inefficient on power conversion. If all you
want to do is preserver the almanac. Lets say a 10 ua need. If on the other
hand you want to keep everything running then larger batteries make sense.
Accept for one gotcha. The chargers on the small UPS's 70-100 watt class are
not really set up to do a good job on a much larger battery set.
With humor they aren't very good for small batteries either.
Regards
Paul.

On Wed, Apr 6, 2011 at 2:25 PM, Murray Greenman
murray.green...@rakon.comwrote:

 Why not just put a bigger battery in your UPS? I have a couple of old
 ones, and they run just fine with an old car battery, and thus give me
 many hours of backup for my Trimble/Nortel GPSDO.

 Just be careful though - in some UPS units the battery is live to the
 mains! The APC ones seem to be OK.

 Murray


 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Mike S]

At 12:15 PM 4/6/2011, Jim Lux wrote...

Isn't your real problem going to be that the oven on the oscillator 
has cooled off?  Or does the GPS lose the whole almanac, so the time 
to first fix is forever?


The more significant problem is that it loses its surveyed position, so 
it takes even more than forever to recover. 



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Chris Albertson]

On Wed, Apr 6, 2011 at 11:25 AM, Murray Greenman
murray.green...@rakon.com wrote:
 Why not just put a bigger battery in your UPS? I have a couple of old
 ones, and they run just fine with an old car battery, and thus give me
 many hours of backup for my Trimble/Nortel GPSDO.

Because with an Oncore you can't even move it or swap a cable.
Anything that causes the power to go down even for an instant clears
the memory and a simple $1 battery will fix this problem and last for
many years.   Yes get the UPS but the Oncore can be greatly improved
by such a simple and cheap fix that it makes sense to do it.

That said, there are commands you can send to the Oncore that will
load an almanac and a survey location.  So even after a memory loss
you can be up running in a few seconds after this data are loaded from
a computer.


-- 
=
Chris Albertson
Redondo Beach, California

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

Oh there you go.
You have made me think. Indeed there are commands that would easily be sent
from a small basic language program on a Basic stamp or SXB or Pic etc etc.
I think its only 2-3 commands also.
But I just need to get off my *() and add the battery before getting silly.
Regards
Paul

On Wed, Apr 6, 2011 at 3:50 PM, Chris Albertson
albertson.ch...@gmail.comwrote:

 On Wed, Apr 6, 2011 at 11:25 AM, Murray Greenman
 murray.green...@rakon.com wrote:
  Why not just put a bigger battery in your UPS? I have a couple of old
  ones, and they run just fine with an old car battery, and thus give me
  many hours of backup for my Trimble/Nortel GPSDO.

 Because with an Oncore you can't even move it or swap a cable.
 Anything that causes the power to go down even for an instant clears
 the memory and a simple $1 battery will fix this problem and last for
 many years.   Yes get the UPS but the Oncore can be greatly improved
 by such a simple and cheap fix that it makes sense to do it.

 That said, there are commands you can send to the Oncore that will
 load an almanac and a survey location.  So even after a memory loss
 you can be up running in a few seconds after this data are loaded from
 a computer.


 --
 =
 Chris Albertson
 Redondo Beach, California

 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup (answer to question)

[Robert Atkinson]

Hi Joe,
Yes you can use a supercap. It will directly replace the ni-cad Just make sure 
the voltage rating is high enough, e.g. 5V 
Ebay item 160495558462 looks good.
 
Robert G8RPI.

--- On Wed, 6/4/11, Joseph Gray jg...@zianet.com wrote:


From: Joseph Gray jg...@zianet.com
Subject: [time-nuts] Oncore battery backup
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Wednesday, 6 April, 2011, 17:00


Recently, the local area had an extended power outage. I have the
Z3801A on a UPS, but the outage lasted over an hour and the UPS
didn't. I have the information about adding a battery to the Oncore to
allow for faster startup. Is it safe to use a supercap instead of a
battery?

Joe Gray
W5JG

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Hal Murray]

paulsw...@gmail.com said:
 The chargers on the small UPS's 70-100 watt class are not really set up to
 do a good job on a much larger battery set.

What's the problem and/or what do the larger units do differently?

--

Several/many years ago, I got a UPS when somebody on this list (I think) 
pointed out that the APC units would tell you the line voltage.  Mostly, I 
wanted something to run a PC that monitors line voltage if/when it went out 
so that worked out nicely.

I looked at the charts and did some quick calculations.  The smaller units 
don't have many watt-hours.  I ended up getting a big unit in order to get 
hours rather than minutes of holdover.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Jim Lux]

On 4/6/11 11:25 AM, Murray Greenman wrote:

Why not just put a bigger battery in your UPS? I have a couple of old
ones, and they run just fine with an old car battery, and thus give me
many hours of backup for my Trimble/Nortel GPSDO.

Just be careful though - in some UPS units the battery is live to the
mains! The APC ones seem to be OK.
The other thing is that some UPS's have a thermal limit on how long they 
can run (e.g. 20 minutes before they melt)... suitable fans might help 
(as opposed to having it in a dust filled box under your desk)


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

Well some good comments about the UPS ability to handle the heat from
running for a long time. Absolutely true. The charger does not deliver
enough current to effectively charge the battery set if its larger then the
original design. As such the battery life is effected up to 50% and
certainly the operating capacity. They build these things cheap as they can
to preserver sales margins and a average life of 2 to 3 years. Regulation of
the charge voltages/currents to optimize SLA life is sloppy.
Don't get me at all wrong. A cheap ups and 2 X batteries should do something
and at the costs they want these days, its pretty amazing actually. Heck
have you seen the cost for a good set of sla batteries these days? I do not
mean homedepot been on the shelf dead for 3 years either.
There is one other reasonable approach. Been around for years and pretty
sure its on the web for the 3801. Essentially float a battery set across the
24 volt input with a good grade charger. This is pretty much how HP does
there RB and CS standards. You do not have the inefficient up conversion
costs of a UPS. Thats exactly how I run my FRS in the basement and on 2 X 14
amp SLA batteries and get around 12 hours as I recall. And thats not killing
the batteries. Bad idea at what they cost these days.
By the way I drop the distribution divider chains and such when I go to
battery Even the leds.
Regards
Paul.

On Wed, Apr 6, 2011 at 4:21 PM, Jim Lux jim...@earthlink.net wrote:

 On 4/6/11 11:25 AM, Murray Greenman wrote:

 Why not just put a bigger battery in your UPS? I have a couple of old
 ones, and they run just fine with an old car battery, and thus give me
 many hours of backup for my Trimble/Nortel GPSDO.

 Just be careful though - in some UPS units the battery is live to the
 mains! The APC ones seem to be OK.

 The other thing is that some UPS's have a thermal limit on how long they
 can run (e.g. 20 minutes before they melt)... suitable fans might help (as
 opposed to having it in a dust filled box under your desk)


 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Chris Albertson]

I remember reading in one of the docs I have for the Oncore that
Motorolla recommended a battery over a cap mainly for practical
reasons.  But now all I can find is some basic specs for what you need
to conect to pin-1 on the header

BATTERY (Externally applied backup power)
Voltage:   2.5 V to 5.25 V
Current:   5 μA typical @ 2.5 V
   100 μA typical @ 5.0 V


On Wed, Apr 6, 2011 at 12:54 PM, Joseph Gray jg...@zianet.com wrote:
 Yes, a UPS isn't the most efficient method of running the GPSDO. It
 was an expedient until the day I run it on batteries.

 As for backing up the Oncore, power outages are not the only reason. I
 may need to power down the GPSDO to add mods or other reasons may
 arise. Having the almanac stored will help.

 I would still like to know if using a supercap is ok. They are made
 for memory backup, so why couldn't I use one for the Oncore? I have a
 few different values on hand.

 Joe Gray
 W5JG

 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.




-- 
=
Chris Albertson
Redondo Beach, California

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Greg Broburg]

I would vote for a lithium AA.

Something like a Tadiran TL5104 3V6 @ 2A10 hrs

Greg

On 4/6/2011 2:43 PM, Chris Albertson wrote:

I remember reading in one of the docs I have for the Oncore that
Motorolla recommended a battery over a cap mainly for practical
reasons.  But now all I can find is some basic specs for what you need
to conect to pin-1 on the header

BATTERY (Externally applied backup power)
Voltage:   2.5 V to 5.25 V
Current:   5 μA typical @ 2.5 V
100 μA typical @ 5.0 V


On Wed, Apr 6, 2011 at 12:54 PM, Joseph Grayjg...@zianet.com  wrote:

Yes, a UPS isn't the most efficient method of running the GPSDO. It
was an expedient until the day I run it on batteries.

As for backing up the Oncore, power outages are not the only reason. I
may need to power down the GPSDO to add mods or other reasons may
arise. Having the almanac stored will help.

I would still like to know if using a supercap is ok. They are made
for memory backup, so why couldn't I use one for the Oncore? I have a
few different values on hand.

Joe Gray
W5JG

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.







___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

Really have to open the 3801 up and go find the magical header.

2011/4/6 Greg Broburg semif...@comcast.net

 I would vote for a lithium AA.

 Something like a Tadiran TL5104 3V6 @ 2A10 hrs

 Greg


 On 4/6/2011 2:43 PM, Chris Albertson wrote:

 I remember reading in one of the docs I have for the Oncore that
 Motorolla recommended a battery over a cap mainly for practical
 reasons.  But now all I can find is some basic specs for what you need
 to conect to pin-1 on the header

 BATTERY (Externally applied backup power)
 Voltage:   2.5 V to 5.25 V
 Current:   5 μA typical @ 2.5 V
100 μA typical @ 5.0 V


 On Wed, Apr 6, 2011 at 12:54 PM, Joseph Grayjg...@zianet.com  wrote:

 Yes, a UPS isn't the most efficient method of running the GPSDO. It
 was an expedient until the day I run it on batteries.

 As for backing up the Oncore, power outages are not the only reason. I
 may need to power down the GPSDO to add mods or other reasons may
 arise. Having the almanac stored will help.

 I would still like to know if using a supercap is ok. They are made
 for memory backup, so why couldn't I use one for the Oncore? I have a
 few different values on hand.

 Joe Gray
 W5JG

 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.





 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup (answer to question)

[WB6BNQ]

Robert,

I completely disagree with such a simple answer !  Lets review the issue here.  
Joe has not given any information as to the
equipment in question, nor has he stated his desired goals other then by 
assumptions based upon his questions.

First, which Oncore receiver is he using ?  If it is the older series such as a 
GT+ or UT+ they are designed to have a
Lithium 3 volt cell soldered onto the board.  The memory draws 5 micro amps at 
3 volts and 100 micro amps at 5 volts.  There
is an external connection available to provide the battery back-up off board 
with a caution of NOT exceeding 5 volts.

The non rechargeable Lithium COIN battery has a discharge function that holds 
its voltage fairly constant right up until the
end.  They will last a very long time with just 5 micro amps of discharge.

The problem with the Super Cap is the charge circuitry could damage the GPS if 
not properly protected.  The Super Cap will
not last as long as the Lithium; we are talking years here under the right 
condition.  Unless you are skilled at changing
small foot print surface mount components, presuming the memory chip is still 
available, you stand the chance of destroying
the receiver.  Why subject yourself to additional unnecessary expense.  Why add 
all that complexity to an otherwise simple
application.  If you add up the cost of the CAP and all the parts to charge it 
and protect the load, I think that would
exceed the cost of the battery.

If your whole existence relies on a single back-up strategy to save your butt, 
then you should not be there in the first
place.  So, I think it is time for Joe to think all of this through with some 
proper goals stated and reasoned thought
applied.

BillWB6BNQ

Robert Atkinson wrote:

 Hi Joe,
 Yes you can use a supercap. It will directly replace the ni-cad Just make 
 sure the voltage rating is high enough, e.g. 5V
 Ebay item 160495558462 looks good.

 Robert G8RPI.

 --- On Wed, 6/4/11, Joseph Gray jg...@zianet.com wrote:

 From: Joseph Gray jg...@zianet.com
 Subject: [time-nuts] Oncore battery backup
 To: Discussion of precise time and frequency measurement 
 time-nuts@febo.com
 Date: Wednesday, 6 April, 2011, 17:00

 Recently, the local area had an extended power outage. I have the
 Z3801A on a UPS, but the outage lasted over an hour and the UPS
 didn't. I have the information about adding a battery to the Oncore to
 allow for faster startup. Is it safe to use a supercap instead of a
 battery?

 Joe Gray
 W5JG

 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.
 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Hal Murray]

paulsw...@gmail.com said:
 The charger does not deliver enough current to effectively charge the
 battery set if its larger then the original design. As such the battery life
 is effected up to 50% and certainly the operating capacity.

I'm missing something.  I'd expect it to just charge slower.  What's wrong 
with that?  (as long as you are willing to wait longer and the unit doesn't 
overheat and ...)

Actually, I'd expect charging slower to be (slightly) better for battery life.

Consider systems that charge batteries from solar cells.  They work fine on 
less than full bright sun.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[Greg Broburg]

From XTOncore Engineering Note

Keep Alive BATT Power . 4.75 - 16 Vdc; 0.3 mA (max) or
. 3V onboard battery; 15 uA typ., 60 uA max.

From UT Plus

Backup Power
Externally applied backup power
Voltage 2.5V to 5.25V
Current 5 μA typical @ 2.5 V
100 μA typical @ 5.0 V
Optional Lithium Battery

Onboard rechargeable cell is charged when main power is on
Voltage 3 V
Capacity 15 mAh
approximately 3 months between charges
Recharge approximately 8 hours for a full charge

From GT

. External 2.5 Vdc to 5.25 Vdc; 5 mA (typ.) @ 2.5 Vdc






On 4/6/2011 2:51 PM, paul swed wrote:

Really have to open the 3801 up and go find the magical header.

2011/4/6 Greg Broburg semif...@comcast.net mailto:semif...@comcast.net

I would vote for a lithium AA.

Something like a Tadiran TL5104 3V6 @ 2A10 hrs

Greg


On 4/6/2011 2:43 PM, Chris Albertson wrote:

I remember reading in one of the docs I have for the Oncore that
Motorolla recommended a battery over a cap mainly for practical
reasons.  But now all I can find is some basic specs for what
you need
to conect to pin-1 on the header

BATTERY (Externally applied backup power)
Voltage:   2.5 V to 5.25 V
Current:   5 μA typical @ 2.5 V
   100 μA typical @ 5.0 V


On Wed, Apr 6, 2011 at 12:54 PM, Joseph Grayjg...@zianet.com
mailto:jg...@zianet.com  wrote:

Yes, a UPS isn't the most efficient method of running the
GPSDO. It
was an expedient until the day I run it on batteries.

As for backing up the Oncore, power outages are not the
only reason. I
may need to power down the GPSDO to add mods or other
reasons may
arise. Having the almanac stored will help.

I would still like to know if using a supercap is ok. They
are made
for memory backup, so why couldn't I use one for the
Oncore? I have a
few different values on hand.

Joe Gray
W5JG

___
time-nuts mailing list -- time-nuts@febo.com
mailto:time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.





___
time-nuts mailing list -- time-nuts@febo.com
mailto:time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[paul swed]

To effectively charge a battery it needs a given amount of current for the
plate area.
Thats why larger batteries actually start in constant current mode.
We are getting slowly but surely off topic.
Regards

On Wed, Apr 6, 2011 at 5:13 PM, Hal Murray hmur...@megapathdsl.net wrote:


 paulsw...@gmail.com said:
  The charger does not deliver enough current to effectively charge the
  battery set if its larger then the original design. As such the battery
 life
  is effected up to 50% and certainly the operating capacity.

 I'm missing something.  I'd expect it to just charge slower.  What's wrong
 with that?  (as long as you are willing to wait longer and the unit doesn't
 overheat and ...)

 Actually, I'd expect charging slower to be (slightly) better for battery
 life.

 Consider systems that charge batteries from solar cells.  They work fine on
 less than full bright sun.


 --
 These are my opinions, not necessarily my employer's.  I hate spam.




 ___
 time-nuts mailing list -- time-nuts@febo.com
 To unsubscribe, go to
 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
 and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup (answer to question)

[vilgo...@bigpond.net.au]

 Hi all,

I had this quandary when using older VP Oncores that I bought at an auction. 
The on board rechargable batteries were defunct and the receivers did not have 
a connection to pin 1 of the header. I solved the problem by connecting a 
schottky diode between the battery terminal on the board and pin 1 so that I 
could put a 3 V Li cell on the mother board. That works very nicely. The diode 
avoids damage to the Li cell from the charging circuit. Rechargeable Li cells 
are very hard to find down here.

Morris
  
 --
 Date: Wed, 06 Apr 2011 13:53:40 -0700
 From: WB6BNQ wb6...@cox.net
 To: Discussion of precise time and frequency measurement
   time-nuts@febo.com
 Subject: Re: [time-nuts] Oncore battery backup (answer to question)
  
 
 First, which Oncore receiver is he using ?  If it is the older series such as 
 a GT+ or UT+ they are designed to have a
 Lithium 3 volt cell soldered onto the board.  The memory draws 5 micro amps 
 at 3 volts and 100 micro amps at 5 volts.  There
 is an external connection available to provide the battery back-up off board 
 with a caution of NOT exceeding 5 volts.
 
 The non rechargeable Lithium COIN battery has a discharge function that holds 
 its voltage fairly constant right up until the
 end.  They will last a very long time with just 5 micro amps of discharge.
 


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Oncore battery backup

[EB4APL]

I did the same to extend the back up time of a couple servers, I used 2 
car batteries because the UPS runs on 24 V.
But be careful, aside for the live battery connection (I couldn't figure 
it out and learned that in the rude way, 220 V here), you can go into 
another problem: some UPSs, mainly the cheap ones intended for backup a 
PC lack the power dissipation capacity to run more than the internal 
battery discharge time, about 10 minutes at full load.  If you connect 
an external battery to extend this time the power transistors can be 
cooked.  I always wondered why these UPSs were not offered in several 
time ranges with the same power rating and this is usually the reason.
Some time ago I used several UPSs manufactured by HP in a project and 
they had provisions for connecting external battery packs.  They  had 
the dissipation department well designed.


Ignacio, EB4APL


On 06/04/2011 20:25, Murray Greenman wrote:

Why not just put a bigger battery in your UPS? I have a couple of old
ones, and they run just fine with an old car battery, and thus give me
many hours of backup for my Trimble/Nortel GPSDO.

Just be careful though - in some UPS units the battery is live to the
mains! The APC ones seem to be OK.

Murray




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.