Re: [Repeater-Builder] Re: battery backup board for micor power supply?

[Scott Zimmerman]

No, I am the dense one. After the day I had, I read your post as asking 
about a battery backup board for in the CHASSIS of the micor station. Purely 
an oops on my part.

I *think* that the only power supply that had battery facilities from 
factory is the switching type power supply. They had a seperate set of 
contacts that went to the battery and an audio lead that went to the 
transmitter so the users could tell when the station was on battery backup. 
On these supplies, the battery power was also run through the 9.6v regulator 
so that voltage was available.

I'm not sure if there was a similar system available for the brute force 
supplies or not.

Sorry about the confusion.
Scott

Scott Zimmerman
Amateur Radio Call N3XCC
474 Barnett Road
Boswell, PA 15531
- Original Message - 
From: "georgiaskywarn" <[EMAIL PROTECTED]>
To: 
Sent: Sunday, February 24, 2008 9:42 PM
Subject: [Repeater-Builder] Re: battery backup board for micor power supply?


> Scott,
> Maybe I am confused...I thought that was the power supply? (the #
> number I gave)  Are you connecting a battery to that 9.6v?
> Sorry for being dense ;-)
> Thanks and 73,
> Robert
> KD4YDC
>
>
>
> --- In Repeater-Builder@yahoogroups.com, "Scott Zimmerman" <[EMAIL PROTECTED]>
> wrote:
>>
>> There is none that I know of. The battery backup option was usually
> provided
>> in the power supply, NOT the station chassis itself. On several that
> I have
>> done that need battery backup, I have attached a 7809 9V regulator
> with a
>> 1N4001 diode in series with the ground terminal to boost the voltage to
>> around 9.6V. I have often thought of building this onto a card that
> would
>> plug into one of the card slots, but I never had the time. This
> would create
>> a situation like the GE station's 10V regulator card.
>>
>> Scott
>>
>> Scott Zimmerman
>> Amateur Radio Call N3XCC
>> 474 Barnett Road
>> Boswell, PA 15531
>> - Original Message - 
>> From: "georgiaskywarn" <[EMAIL PROTECTED]>
>> To: 
>> Sent: Sunday, February 24, 2008 6:26 PM
>> Subject: [Repeater-Builder] battery backup board for micor power supply?
>>
>>
>> > Is there such a beast?  What is the number for that?  I have a
>> > TPN1110B power supply.
>> > Thanks,
>> > Robert
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> >
>> > -- 
>> > No virus found in this incoming message.
>> > Checked by AVG Free Edition.
>> > Version: 7.5.516 / Virus Database: 269.21.0/1296 - Release Date:
> 2/24/2008
>> > 12:19 PM
>> >
>> >
>>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.516 / Virus Database: 269.21.0/1296 - Release Date: 2/24/2008 
> 12:19 PM
>
> 

[Repeater-Builder] Re: battery backup board for micor power supply?

[georgiaskywarn]

Scott,
Maybe I am confused...I thought that was the power supply? (the #
number I gave)  Are you connecting a battery to that 9.6v?
Sorry for being dense ;-)
Thanks and 73,
Robert
KD4YDC



--- In Repeater-Builder@yahoogroups.com, "Scott Zimmerman" <[EMAIL PROTECTED]>
wrote:
>
> There is none that I know of. The battery backup option was usually
provided 
> in the power supply, NOT the station chassis itself. On several that
I have 
> done that need battery backup, I have attached a 7809 9V regulator
with a 
> 1N4001 diode in series with the ground terminal to boost the voltage to 
> around 9.6V. I have often thought of building this onto a card that
would 
> plug into one of the card slots, but I never had the time. This
would create 
> a situation like the GE station's 10V regulator card.
> 
> Scott
> 
> Scott Zimmerman
> Amateur Radio Call N3XCC
> 474 Barnett Road
> Boswell, PA 15531
> - Original Message - 
> From: "georgiaskywarn" <[EMAIL PROTECTED]>
> To: 
> Sent: Sunday, February 24, 2008 6:26 PM
> Subject: [Repeater-Builder] battery backup board for micor power supply?
> 
> 
> > Is there such a beast?  What is the number for that?  I have a
> > TPN1110B power supply.
> > Thanks,
> > Robert
> >
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> > -- 
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.5.516 / Virus Database: 269.21.0/1296 - Release Date:
2/24/2008 
> > 12:19 PM
> >
> >
>

[Repeater-Builder] Re: Battery backup

[Dave VanHorn]

--- In Repeater-Builder@yahoogroups.com, Joe Montierth
<[EMAIL PROTECTED]> wrote:
>
> The simplest way is just to get the IOTA supply and
> float it across the battery. Thats it, nothing else
> needed. Get an IOTA big enough to power whatever you
> have, and still have some left over for charging. You
> don't need (or want) diodes, resistors, or relays.


I have one caveat with the Iota.

In my system it resulted in a "horrible noise" because the repeater
itself is located about 10' away from the antenna, and the Iota has
some significant energy internally at about 600kHz.  That mixed with
my TX, and created two sidebands, one of which fed back into my RX. 
It would come and go dependent on load/temperature.

If you're mounted far enough away, then that shouldn't be a problem.

[Repeater-Builder] Re: Battery backup

[Doug Dickinson]

Try this link:
   
  http://www.westmountainradio.com/SuperPWRgate.htm
   
  Doug

RE: [SPAM] Re: [Repeater-Builder] Re: Battery backup

[Fred Flowers]

This is what he was talking about.

 

http://www.westmountainradio.com/SuperPWRgate.htm

 

 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Doug Zastrow
Sent: Wednesday, January 10, 2007 10:23 PM
To: Repeater-Builder@yahoogroups.com
Subject: [SPAM] Re: [Repeater-Builder] Re: Battery backup

 

Hi Doug,

 

I found what I believe to be the Powergate web site at
http://www.powergatellc.com/ but could not find the PW40S under any of the
categories listed nor through product no. search.

 

Am I at the right web site?  Any hints on finding this model?

 

Doug Z.

- Original Message - 

From: Doug Dickinson <mailto:[EMAIL PROTECTED]>  

To: Repeater-Builder@yahoogroups.com 

Sent: Tuesday, January 09, 2007 7:18 PM

Subject: [Repeater-Builder] Re: Battery backup

 

The best arrangement I have seen so far is the Powergate PW40S which has the
built-in 3 stage charger. I have used them and they are really good with a
zero time switchover so none of the little electrons in the controller get
confused and reset or worse, lockup the controller. It also charges the
battery the RIGHT way, with a 3 stage charger. It can be duplicated I am
sure, but at the price, I just would buy it and spend the time tinkering
with the RF for a good repeater.

 

IMHO

 

Doug KC0SDQ

 

Re: [Repeater-Builder] Re: Battery backup

[Charles Schmell]

The Powergate PG40S is  sold by West Mountain Radio
see:
"http://www.westmountainradio.com/SuperPWRgate.htm"; 
(delete the quote marks)

Charles, KB3CEZ

--- Doug Zastrow <[EMAIL PROTECTED]> wrote:

> Hi Doug,
> 
> I found what I believe to be the Powergate web site
> at http://www.powergatellc.com/ but could not find
> the PW40S under any of the categories listed nor
> through product no. search.
> 
> Am I at the right web site?  Any hints on finding
> this model?
> 
> Doug Z.
>   - Original Message - 
>   From: Doug Dickinson 
>   To: Repeater-Builder@yahoogroups.com 
>   Sent: Tuesday, January 09, 2007 7:18 PM
>   Subject: [Repeater-Builder] Re: Battery backup
> 
> 
>   The best arrangement I have seen so far is the
> Powergate PW40S which has the built-in 3 stage
> charger. I have used them and they are really good
> with a zero time switchover so none of the little
> electrons in the controller get confused and reset
> or worse, lockup the controller. It also charges the
> battery the RIGHT way, with a 3 stage charger. It
> can be duplicated I am sure, but at the price, I
> just would buy it and spend the time tinkering with
> the RF for a good repeater.
> 
>   IMHO
> 
>   Doug KC0SDQ
>



 

Do you Yahoo!?
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com

Re: [Repeater-Builder] Re: Battery backup

[Doug Zastrow]

Hi Doug,

I found what I believe to be the Powergate web site at 
http://www.powergatellc.com/ but could not find the PW40S under any of the 
categories listed nor through product no. search.

Am I at the right web site?  Any hints on finding this model?

Doug Z.
  - Original Message - 
  From: Doug Dickinson 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Tuesday, January 09, 2007 7:18 PM
  Subject: [Repeater-Builder] Re: Battery backup


  The best arrangement I have seen so far is the Powergate PW40S which has the 
built-in 3 stage charger. I have used them and they are really good with a zero 
time switchover so none of the little electrons in the controller get confused 
and reset or worse, lockup the controller. It also charges the battery the 
RIGHT way, with a 3 stage charger. It can be duplicated I am sure, but at the 
price, I just would buy it and spend the time tinkering with the RF for a good 
repeater.

  IMHO

  Doug KC0SDQ
   

[Repeater-Builder] Re: Battery backup

[Doug Dickinson]

The best arrangement I have seen so far is the Powergate PW40S which has the 
built-in 3 stage charger. I have used them and they are really good with a zero 
time switchover so none of the little electrons in the controller get confused 
and reset or worse, lockup the controller. It also charges the battery the 
RIGHT way, with a 3 stage charger. It can be duplicated I am sure, but at the 
price, I just would buy it and spend the time tinkering with the RF for a good 
repeater.
   
  IMHO
   
  Doug KC0SDQ

RE: [Repeater-Builder] Re: Battery backup

[Joe Montierth]

The simplest way is just to get the IOTA supply and
float it across the battery. Thats it, nothing else
needed. Get an IOTA big enough to power whatever you
have, and still have some left over for charging. You
don't need (or want) diodes, resistors, or relays.

It shouldn't be that easy, but in this case it is. I
have some commercial sites that we run this way
without problems. We have some with big Astron
supplies, but we are changing them out to the IOTA.
The new supplies will pay for themselves in a couple
of years due to higher efficiency over the linear
Astrons.

The Astrons will also work well, with very minor mods.
You still don't need the diodes. We have used the
Astrons for over 12 years this way, the IOTAs for
about 2.5 .

Joe


--- Richard <[EMAIL PROTECTED]> wrote:

> I had a similar experience: I had a couple of deep
> cycle batteries in an
> outdoor steel enclosure that I would charge
> periodically by connecting a
> standard automotive charger. At times I would forget
> it was connected, so
> eventually the batteries were cooked. After some
> research on the web, I
> settled on an IOTA DLS-15 power supply with an IQ4
> smart charge controller.
> It is connected full time to the (new) batteries,
> and I only have to add
> water every couple of months. I have not noted any
> kind of noise generated
> by the charger. This setup works very well for me.
> 
> Richard, N7TGB
> 
> 
>   -Original Message-
>   From: Repeater-Builder@yahoogroups.com
> [mailto:[EMAIL PROTECTED] Behalf
> Of Dave Schmidt
>   Sent: Tuesday, January 09, 2007 9:26 AM
>   To: Repeater-Builder@yahoogroups.com
>   Subject: Re: [Repeater-Builder] Re: Battery backup
> 
> 
> 
>   I have to agree with Dave. Using the proper
> charger or power supply for
> keeping the batts up.  I have my batteries housed in
> a stainless steel
> enclosure that is anchored into concrete outside my
> ham shack. I learned the
> hard way about using the proper charger... I just
> tapped into my repeaters
> 25amp power supply to keep the batteries charged
> till I could make a
> charging circuit ... a, big mistake. That
> charging circuit  - oops, I
> forgot... about a month of operation,  I was working
> around the tower and
> smelled what smelled like battery acid. Sure enough,
> I cooked both flooded
> lead acid batteries and they were fuming acid vapor.
> Lucky the box is a
> comercial built ss box.
> 
>   Now, after that incident, I have been using a
> marine (boat) "smart
> charger" which automatically determines wether to
> charge or float. Since
> battery chargers are, ummm, quite noisy and not all
> that nice on batteries
> due to most of them only using a half wave recifier
> ( AC is not nice on
> batteries ). I added a 25A bridge rectifier and
> added extra filtering which
> is just a big Motorola mobile power filter block
> from the Micor dayz. It is
> also isolated using some BIG diodes - like Dave's,
> the threaded case type
> diodes which is bolted to a heatsink.
> 
>   The system is running well in this configuration.
> If using flooded type
> batteries, do a monthly check on acid levels !   I
> recomend AGM batteries
> ( Absorbed Glass Mat ) or if that is a little pricy,
> get marine deep cycle
> batteries - do not use automotive batteries unless
> you just absolutely half
> to.
> 
>   Dave / N9NLU
>   www.kmcg.org
> 
> 
> 
> 
> 
> 
> 
>   On 1/9/07, ve7ltd <[EMAIL PROTECTED]> wrote:
> I have had good luck using a pair of diodes to
> isolate a power supply
> from a charging circuit. I essentially have a
> Statpower 10amp battery
> charger (specifically designed for the flooded
> cells I am using). The
> batteries float on the charger voltage when the
> AC power is available.
> The battery positive lead then feeds through a
> diode and joins
> the "positive power bus" of my repeaters. Using
> a proper charger is the
> most important part so you dont boil off the
> electrolyte in your
> batteries.
> 
> The positive power bus is fed from a large GE
> power supply. The
> positive lead from the power supply feeds
> through a diode to feed the
> power bus.
> 
> The idea of using a diodes is to keep the higher
> voltage of the power
> supply from passing current into the batteries
> when AC is available,
> and vice versa when AC is off.
> 
> However, if you are using a high power PA or
> your repeater draws more
> than about 20 AMPs on TX, you have to be careful
> of your choices of
> diode. I use large feedthrough diodes, mounted
> on large heatsinks

Re: [Repeater-Builder] Re: Battery backup

[Mike Morris WA6ILQ]

One source of (almost) free diode pairs is any alternator shop.  The
common configuration of diodes in an alternator has three on a
plate, and two plates.  One plate is common anode, the other plate
is common cathode.

The common failure mode is that one diode opens or shorts and the
technician replaces the entire plate. This means that two perfectly
20 to 75 amp premounted diodes (depending on the alternator
current rating) goes in the trash.  Some shops press out the
good diodes and reuse them, many don't.

At one site I've seen an alternator diode plate with two diodes (it was
obvious that the bad diode was on the end that was hacksawed off)
mounted to an insulator block and that on a rack panel.

Mike WA6ILQ

At 09:25 AM 01/09/07, you wrote:
I have to agree with Dave. Using the proper charger or power supply 
for keeping the batts up.  I have my batteries housed in a stainless 
steel enclosure that is anchored into concrete outside my ham shack. 
I learned the hard way about using the proper charger... I just 
tapped into my repeaters 25amp power supply to keep the batteries 
charged till I could make a charging circuit ... a, big mistake. 
That charging circuit  - oops, I forgot... about a month of 
operation,  I was working around the tower and smelled what smelled 
like battery acid. Sure enough, I cooked both flooded lead acid 
batteries and they were fuming acid vapor. Lucky the box is a 
comercial built ss box.


Now, after that incident, I have been using a marine (boat) "smart 
charger" which automatically determines wether to charge or float. 
Since battery chargers are, ummm, quite noisy and not all that nice 
on batteries due to most of them only using a half wave recifier ( 
AC is not nice on batteries ). I added a 25A bridge rectifier and 
added extra filtering which is just a big Motorola mobile power 
filter block from the Micor dayz. It is also isolated using some BIG 
diodes - like Dave's, the threaded case type diodes which is bolted 
to a heatsink.


The system is running well in this configuration. If using flooded 
type batteries, do a monthly check on acid levels !   I recomend AGM 
batteries ( Absorbed Glass Mat ) or if that is a little pricy, get 
marine deep cycle batteries - do not use automotive batteries unless 
you just absolutely half to.


Dave / N9NLU
www.kmcg.org







On 1/9/07, ve7ltd <[EMAIL PROTECTED]> wrote:

I have had good luck using a pair of diodes to isolate a power supply
from a charging circuit. I essentially have a Statpower 10amp battery
charger (specifically designed for the flooded cells I am using). The
batteries float on the charger voltage when the AC power is available.
The battery positive lead then feeds through a diode and joins
the "positive power bus" of my repeaters. Using a proper charger is the
most important part so you dont boil off the electrolyte in your
batteries.

The positive power bus is fed from a large GE power supply. The
positive lead from the power supply feeds through a diode to feed the
power bus.

The idea of using a diodes is to keep the higher voltage of the power
supply from passing current into the batteries when AC is available,
and vice versa when AC is off.

However, if you are using a high power PA or your repeater draws more
than about 20 AMPs on TX, you have to be careful of your choices of
diode. I use large feedthrough diodes, mounted on large heatsinks, but
on lower current draw you could get away with using a smaller bridge
rectifier mounted to an unpainted metal piece in your repeater cabinet
with some heatsink compound.

Dave Cameron
VE7LTD

--- In 
Repeater-Builder@yahoogroups.com, 
"wm5c" <[EMAIL PROTECTED]>

wrote:
>
> Hi,
>
> New member here. Thanks for allowing me to join.
> Our club has acquired some large lead-acid 12v batteries we would
like
> to use to back up our repeater in emergency situations. Does anyone
> know of a good (but simple and inexpensive [we are a very small group
> in a very small town]) circuit to accomplish this? Any input would
be
> appreciated.
>
> Danny WM5C
> Heart Of Texas Ham Operators Group (HOTHOG)
> Brady, TX
> www.hothog.org
>

RE: [Repeater-Builder] Re: Battery backup

[Richard]

I had a similar experience: I had a couple of deep cycle batteries in an
outdoor steel enclosure that I would charge periodically by connecting a
standard automotive charger. At times I would forget it was connected, so
eventually the batteries were cooked. After some research on the web, I
settled on an IOTA DLS-15 power supply with an IQ4 smart charge controller.
It is connected full time to the (new) batteries, and I only have to add
water every couple of months. I have not noted any kind of noise generated
by the charger. This setup works very well for me.

Richard, N7TGB


  -Original Message-
  From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] Behalf Of Dave Schmidt
  Sent: Tuesday, January 09, 2007 9:26 AM
  To: Repeater-Builder@yahoogroups.com
  Subject: Re: [Repeater-Builder] Re: Battery backup



  I have to agree with Dave. Using the proper charger or power supply for
keeping the batts up.  I have my batteries housed in a stainless steel
enclosure that is anchored into concrete outside my ham shack. I learned the
hard way about using the proper charger... I just tapped into my repeaters
25amp power supply to keep the batteries charged till I could make a
charging circuit ... a, big mistake. That charging circuit  - oops, I
forgot... about a month of operation,  I was working around the tower and
smelled what smelled like battery acid. Sure enough, I cooked both flooded
lead acid batteries and they were fuming acid vapor. Lucky the box is a
comercial built ss box.

  Now, after that incident, I have been using a marine (boat) "smart
charger" which automatically determines wether to charge or float. Since
battery chargers are, ummm, quite noisy and not all that nice on batteries
due to most of them only using a half wave recifier ( AC is not nice on
batteries ). I added a 25A bridge rectifier and added extra filtering which
is just a big Motorola mobile power filter block from the Micor dayz. It is
also isolated using some BIG diodes - like Dave's, the threaded case type
diodes which is bolted to a heatsink.

  The system is running well in this configuration. If using flooded type
batteries, do a monthly check on acid levels !   I recomend AGM batteries
( Absorbed Glass Mat ) or if that is a little pricy, get marine deep cycle
batteries - do not use automotive batteries unless you just absolutely half
to.

  Dave / N9NLU
  www.kmcg.org







  On 1/9/07, ve7ltd <[EMAIL PROTECTED]> wrote:
I have had good luck using a pair of diodes to isolate a power supply
from a charging circuit. I essentially have a Statpower 10amp battery
charger (specifically designed for the flooded cells I am using). The
batteries float on the charger voltage when the AC power is available.
The battery positive lead then feeds through a diode and joins
the "positive power bus" of my repeaters. Using a proper charger is the
most important part so you dont boil off the electrolyte in your
batteries.

The positive power bus is fed from a large GE power supply. The
positive lead from the power supply feeds through a diode to feed the
power bus.

The idea of using a diodes is to keep the higher voltage of the power
supply from passing current into the batteries when AC is available,
and vice versa when AC is off.

However, if you are using a high power PA or your repeater draws more
than about 20 AMPs on TX, you have to be careful of your choices of
diode. I use large feedthrough diodes, mounted on large heatsinks, but
on lower current draw you could get away with using a smaller bridge
rectifier mounted to an unpainted metal piece in your repeater cabinet
with some heatsink compound.

Dave Cameron
VE7LTD

--- In Repeater-Builder@yahoogroups.com, "wm5c" <[EMAIL PROTECTED]>
wrote:
>
> Hi,
>
> New member here. Thanks for allowing me to join.
> Our club has acquired some large lead-acid 12v batteries we would
like
> to use to back up our repeater in emergency situations. Does anyone
> know of a good (but simple and inexpensive [we are a very small group
> in a very small town]) circuit to accomplish this? Any input would
be
> appreciated.
>
> Danny WM5C
> Heart Of Texas Ham Operators Group (HOTHOG)
> Brady, TX
> www.hothog.org
>






  

Re: [Repeater-Builder] Re: Battery backup

[Dave Schmidt]

I have to agree with Dave. Using the proper charger or power supply for
keeping the batts up.  I have my batteries housed in a stainless steel
enclosure that is anchored into concrete outside my ham shack. I learned the
hard way about using the proper charger... I just tapped into my repeaters
25amp power supply to keep the batteries charged till I could make a
charging circuit ... a, big mistake. That charging circuit  - oops, I
forgot... about a month of operation,  I was working around the tower and
smelled what smelled like battery acid. Sure enough, I cooked both flooded
lead acid batteries and they were fuming acid vapor. Lucky the box is a
comercial built ss box.

Now, after that incident, I have been using a marine (boat) "smart charger"
which automatically determines wether to charge or float. Since battery
chargers are, ummm, quite noisy and not all that nice on batteries due to
most of them only using a half wave recifier ( AC is not nice on batteries
). I added a 25A bridge rectifier and added extra filtering which is just a
big Motorola mobile power filter block from the Micor dayz. It is also
isolated using some BIG diodes - like Dave's, the threaded case type diodes
which is bolted to a heatsink.

The system is running well in this configuration. If using flooded type
batteries, do a monthly check on acid levels !   I recomend AGM batteries (
Absorbed Glass Mat ) or if that is a little pricy, get marine deep cycle
batteries - do not use automotive batteries unless you just absolutely half
to.

Dave / N9NLU
www.kmcg.org







On 1/9/07, ve7ltd <[EMAIL PROTECTED]> wrote:


  I have had good luck using a pair of diodes to isolate a power supply
from a charging circuit. I essentially have a Statpower 10amp battery
charger (specifically designed for the flooded cells I am using). The
batteries float on the charger voltage when the AC power is available.
The battery positive lead then feeds through a diode and joins
the "positive power bus" of my repeaters. Using a proper charger is the
most important part so you dont boil off the electrolyte in your
batteries.

The positive power bus is fed from a large GE power supply. The
positive lead from the power supply feeds through a diode to feed the
power bus.

The idea of using a diodes is to keep the higher voltage of the power
supply from passing current into the batteries when AC is available,
and vice versa when AC is off.

However, if you are using a high power PA or your repeater draws more
than about 20 AMPs on TX, you have to be careful of your choices of
diode. I use large feedthrough diodes, mounted on large heatsinks, but
on lower current draw you could get away with using a smaller bridge
rectifier mounted to an unpainted metal piece in your repeater cabinet
with some heatsink compound.

Dave Cameron
VE7LTD

--- In Repeater-Builder@yahoogroups.com,
"wm5c" <[EMAIL PROTECTED]>
wrote:
>
> Hi,
>
> New member here. Thanks for allowing me to join.
> Our club has acquired some large lead-acid 12v batteries we would
like
> to use to back up our repeater in emergency situations. Does anyone
> know of a good (but simple and inexpensive [we are a very small group
> in a very small town]) circuit to accomplish this? Any input would
be
> appreciated.
>
> Danny WM5C
> Heart Of Texas Ham Operators Group (HOTHOG)
> Brady, TX
> www.hothog.org
>

[Repeater-Builder] Re: Battery backup

[ve7ltd]

I have had good luck using a pair of diodes to isolate a power supply 
from a charging circuit. I essentially have a Statpower 10amp battery 
charger (specifically designed for the flooded cells I am using). The 
batteries float on the charger voltage when the AC power is available. 
The battery positive lead then feeds through a diode and joins 
the "positive power bus" of my repeaters. Using a proper charger is the 
most important part so you dont boil off the electrolyte in your 
batteries.

The positive power bus is fed from a large GE power supply. The 
positive lead from the power supply feeds through a diode to feed the 
power bus.

The idea of using a diodes is to keep the higher voltage of the power 
supply from passing current into the batteries when AC is available, 
and vice versa when AC is off.

However, if you are using a high power PA or your repeater draws more 
than about 20 AMPs on TX, you have to be careful of your choices of 
diode. I use large feedthrough diodes, mounted on large heatsinks, but 
on lower current draw you could get away with using a smaller bridge 
rectifier mounted to an unpainted metal piece in your repeater cabinet 
with some heatsink compound.

Dave Cameron
VE7LTD



--- In Repeater-Builder@yahoogroups.com, "wm5c" <[EMAIL PROTECTED]> 
wrote:
>
> Hi,
> 
> New member here.  Thanks for allowing me to join.
> Our club has acquired some large lead-acid 12v batteries we would 
like 
> to use to back up our repeater in emergency situations.  Does anyone 
> know of a good (but simple and inexpensive [we are a very small group 
> in a very small town]) circuit to accomplish this?  Any input would 
be 
> appreciated.
> 
> Danny WM5C
> Heart Of Texas Ham Operators Group (HOTHOG)
> Brady, TX
> www.hothog.org
>