Power Supply Requirements

[snoozer]

hello,

would it be possible to get precise specs regarding the power supply for Rocket, Nano and Bullet ?

We intend to use some Rockets and Nanos on battery powered remote sites. we usually have either 24V or 48V available as stabilized power supply. if i could get the safe working voltage range for above devices it would be great to figure out if i need a different regulator. the rockets for example come with a 24V PS and the Nanos with a 15V PS. would be nice if i could use 24V on both.

kind regards
Jan

[WHT]

The Nano will work up to 25 volts. But personally, I don't get a warm and fuzzy feeling running anything that close to its max allowed input voltage. Stick a fifty foot patch cable in there.

[UBNT-Mike.Ford]

hello,

would it be possible to get precise specs regarding the power supply for Rocket, Nano and Bullet ?

We intend to use some Rockets and Nanos on battery powered remote sites. we usually have either 24V or 48V available as stabilized power supply. if i could get the safe working voltage range for above devices it would be great to figure out if i need a different regulator. the rockets for example come with a 24V PS and the Nanos with a 15V PS. would be nice if i could use 24V on both.

kind regards
Jan

Hello,

The units operate from 12V to 24V without issues.

Thanks,

Mike

[opampca]

Hello,

The units operate from 12V to 24V without issues.

Thanks,

Mike

Mike,
Is this for all Ubiquiti products ?
If not, is it possible to know the limits of each ?
Thank you
Richard

[Dave-D]

Richard, the absolute min/max for all
Ubiquiti AirMAX radios is 10.5 to 25V
at the radio's connector.

You would be well advised to never
go below 12V or above 24V. So I'm
not sure what your goal is when you
ask this. For example, if you operate
on a 24V PoE supply with a short
piece of cable, it's not hard to exceed
25V. If you try to run a radio on a
12V battery, it's likely to dip below
11V on low charge. Neither is good. Dave

[snoozer]

with batteries there is mainly the problem that the voltage by charging can be considerably higher than the nominal battery voltage. we use solar panels and wind generators as well as battery buffered mains power. i all cases the real life battery voltage while charging exceeds the nominal voltage of 24V and can be up to 28-29V. to avoid problems with that i usually use 24V voltage regulators per consumer like the 78S24, they usually have an output little lower than 24V and work reliably since years.

thanks for the information about the limits anyway, i can now be sure i can use 24V.

regards
Jan

[aaron]

If you have power supply that is over 24V you could do a quick and dirty with a 1 to 3 rectifier diodes that can handle 1-2Amps, each (silicone)diode will drop .6-.7 volts but using more than 3 (if you need to drop the voltage more than 1.8Volts) it would be more cost effective to use something like the 78S18 or 78S24. looks like the datasheet says the 78S18 can take 35Volts input and the 78S24 can take 40V.

I think I'd go for the 18volts cause the input needs to be about 2 volts higher than the output voltage when your pushing 1Amp through the 78S18. If your 24V battery pack which on good charge will be about 25.2Volts happens to drop to say 23.8Volts the 24Volt regulators might behave "funny". Wouldn't hurt to have a couple of "filter" capacitors and inductors on the in and out just for $hits.

[Dave-D]

Snoozer, if you have 48Vdc available, the
'instant 803.2af adapter' is made for you!
It's placed in-line at the radio, and down-
converts the 48V to a reliable 18Vdc. It's
effectively a regulator, and has some
extra transient protection as well.

You don't have to worry about cable length
or losses--just 'plug-n-play'. Dave

[PJ]

M series "Airmax Products"
power supply supports 12-24VDC

The main Regulator has a range from 4.5V to 28V
However the recommended range is 12-24V for typical use depending on Your cable runs and power rating of the power supply you use.
Typically You do not want to use higher then 0.7A on long cable runs using higher voltage is better lower current.

For example NS5M
You could use 9VDC with about 1A, yes the unit will work OK, but Your cable run will be very short.

I have tested 100ft cable CAT5 with 15V it is OK
I have tested 200ft cable CAT5 with 15V and it failed,
I have tested 250ft cable CAT5 with 24V it is OK

[Dave-D]

PJ, I don't know where you got all this.
The absolute minimum for AirMAX radios
is 10.5V at the connector. They will not
run on 4.5V. And there is a diode to
clamp the top end at about 26.5V.

A 9V PoE supply will not work OK.
For most radios, it won't work at all. Dave

[PJ]

Dave,
I never said they would run on 4.5V, I just mentioned the Voltage range for the main regulator, As User Snoozer requested more detail specs.
I clearly said the recommended range is 12V to 24V
And yes the Radio units do have TVS diode protection rated for 24V, will trip around 26V the TVS Diode does have a min max tolerance for tripping.
If Your Power supply is rated for 24V you should be OK there is enough margin of error, I have seen plenty of power supplies rated for 24V outputting 26V.

[snoozer]

aaron, i have capacitors on the input and output like shown here:

http://www.elektronik-kompendium.de/sites/bau/schalt/02043011.gif

i like to stay with the components i can easy replace and get anywhere. btw i am using the 78S24 in places where i often have even less than 24V input (solar panel sites) and they work fine, just the output is lower. so far i never had any problems.

thanks for your help guys !

Jan