I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.


JImmie

On Feb 14, 12:51 pm, wrote:
I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.

JImmie

Do you plan on leaving the batteries in the unit? They act as a large
filter capacitor for the unit. If you take them out, you will need to
use some rather large filter capacitors to get anything close to DC.
If you have an oscilloscope, look at the waveform with the batteries
in place and with them disconnected. That will tell you how badly you
need filtering.

Good luck,
Paul KD7HB

On Feb 14, 2:51�pm, wrote:
I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.

JImmie

It should work OK. The only problem I see is if the charger is not
regulated. It probably is to keep the batteries from overcharging. I
bet that baby is heavy.
I have found a 48 volt 20 amp supply that I use with my EB104 Amp
that is about 8 lbs. The Amp itself is about 5 lbs., so I have 600
watts out in under 15 lbs. or .4 oz./watt.
The power supply is less than $300 USD including shipping. If you
want more details, let me know.

73 Gary N4AST

wrote:
I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.

Bear in mind that even with light use, the batteries will eventually
have to be replaced. APC, for example, rates their SOHO UPS devices
with replaceable batteries at 2-3 years between change-ups.

However, this is an excellent way of maintaining a decent shack when the
lights go out.
--
clvrmnky

Direct replies to this address will be blacklisted. Replace "spamtrap"
with my name to contact me directly.

Jimmie D wrote:
"Clever Monkey" wrote in message
...
wrote:
I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.

Bear in mind that even with light use, the batteries will eventually have
to be replaced. APC, for example, rates their SOHO UPS devices with
replaceable batteries at 2-3 years between change-ups.

However, this is an excellent way of maintaining a decent shack when the
lights go out.

I have some 100 amp/hr batteries, I was wondering if they might work with
the UPS charger.

Jimmie


I use a small APC UPS in the outdoor shack with a 110Ah camping battery,
the small charger works OK but does take a few days to recharge. I added
a small fan to the heat sink of the inverter as it tends to get a bit
hot. The chargers need a battery connected as a load as they are not
pure DC.

Gerry....

Well I have a Cyberpower 3000 sine wave output ups in the basement fed with
two banks of 4 12 vdc 38 amp hr Hawker absorpion gas mat batteries wired in
series...The ups specifies 48 vdc battery banks, normally of much smaller
capacity. It just takes a long time to get the batteries charged.
Works perfectly well for me!
One think I did do is build a Faraday shield out some aluminum screening
over the Cyberpower ups and the battery pack, gounded to an 8' ground rod
thru the basement wall to keep the inverter noise out of the hf rigs.
The Cyberpower feeds the radio station's power supplys and the pc on the
main floor thru a dedicated ac outlet.

"Jimmie D" wrote in message
...

"Clever Monkey" wrote in message
...
wrote:
I was thinking about using a UPS as a power supply for an amplifier.
The UPS is rated at over 2KW and uses 48 volts on the DC bus. I have
tried powering an amp directly from the batteries and it seems to work
OK. Battery pack is rate at 20 amp/hr. The inverter side of the UPS is
dead but the charger side is still functional. The plan is to remove
the inverter circuit completely. Can anyone think of anything wrong
with doing this.

Bear in mind that even with light use, the batteries will eventually have
to be replaced. APC, for example, rates their SOHO UPS devices with
replaceable batteries at 2-3 years between change-ups.

However, this is an excellent way of maintaining a decent shack when the
lights go out.

I have some 100 amp/hr batteries, I was wondering if they might work with
the UPS charger.

Jimmie

Jimmie D wrote:
Last night I hooked up the 4 100 amp hour batteries to the inverter and it
shut down. Appararently it has some type of overcurrent protection. So I
hooked my big auto shop station type battery charger up to them and let them
charge over night. This AM when I connected the batteries to the inverter it
just hummed right along. It appears that as long as I dont let the batteries
get severly discharged I will be OK.

In other words, as long as you don't use the extra capacity you got those
batteries for.

--
B. Hussein Obama won't wear an American flag on his lapel, or put his hand over
his heart during the national anthem, but prominently displayed in his Houston
campaign office are TWO Cuban flags, each with a picture of Che Guevara
superimposed on it.

clifto wrote:
Jimmie D wrote:
Last night I hooked up the 4 100 amp hour batteries to the inverter and it
shut down. Appararently it has some type of overcurrent protection. So I
hooked my big auto shop station type battery charger up to them and let them
charge over night. This AM when I connected the batteries to the inverter it
just hummed right along. It appears that as long as I dont let the batteries
get severly discharged I will be OK.

In other words, as long as you don't use the extra capacity you got those
batteries for.




I think you'd be better off building/buying a 48V battery charger.
The little charger in the UPS is usually a trickle-charger type,and as
you found out,doesn't like bigger loads much.

Say you hit the PTT on your favorite rig,and the voltage dips a bit
-perhaps below the UPS chargers "happy point" and it throws a fit while
you're on the air.