On the other hand, I don’t think you need to design for as low as 6V.
From: Chuck McCown
Sent: Wednesday, September 09, 2015 1:58 PM
To: af@afmug.com
Subject: Re: [AFMUG] GIGE-POE-APC Hot?
They don’t throw off much heat, the resistor is rated at 0.5 watt and it has
never failed.
I think the resistor is a 10K so at [60V – 1.2 V (for the LED)] Squared over
10K = 345 milliwatts of heat.
Not much heat to get rid of.
Temperature is a different thing. The temp of the component will be high at
high voltages if you put your finger on it. But it isn’t going to add much to
the active load and if it is running at 125F, your box raises another 20
degrees, 145F is not going to get too hot for the solder to melt.
From: George Skorup
Sent: Wednesday, September 09, 2015 12:38 PM
To: af@afmug.com
Subject: Re: [AFMUG] GIGE-POE-APC Hot?
I did mention this here when I was bench testing powering an AF24. My Traco was
floating at 55 volts. The radio ran fine.
It's not that it's powering the radio and getting hot. If you feed the card
with 50+ volts, the LED still gets hot. I remember that Chuck did say it should
be fine up to 60VDC.
I'm going to be using a lot more of these on more site 48VDC conversions. So
Chuck, is this something that can be changed? Is there any risk of severe
overheating if I have these running in a hot enclosure? Some sites we just
can't do ventilation because of grain dust and things of that nature.
On 9/9/2015 11:04 AM, Josh Baird wrote:
So, there are people here powering AF24's with 54-55 (float) voltage without
issues? Just trying to rule this out.
On Wed, Sep 9, 2015 at 11:47 AM, Chuck McCown <ch...@wbmfg.com> wrote:
No, 54-55 is a good float voltage for lead acid 48 VDC batteries.
The voltage itself has nothing to do with the data.
Too much current could affect it, but in my testing, the chip with the
magnetics will unsolder itself before it stops passing data.
From: Josh Baird
Sent: Wednesday, September 09, 2015 9:30 AM
To: af@afmug.com
Subject: Re: [AFMUG] GIGE-POE-APC Hot?
Stock is 50V. I'm running them directly off a Traco TSP (~54V). I wonder
if this is why the ethernet keeps dropping.
On Wed, Sep 9, 2015 at 11:27 AM, Mathew Howard <mhoward...@gmail.com> wrote:
The stock AF24 power supply is 50v, if I remember correctly.
On Wed, Sep 9, 2015 at 9:37 AM, Josh Luthman
<j...@imaginenetworksllc.com> wrote:
Isn't AF24 only 48v?
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Wed, Sep 9, 2015 at 10:33 AM, Chuck McCown <ch...@wbmfg.com> wrote:
OK, there are some half watt resistors in that area. When running at
55 volts limiting current for the LEDs they do get hot. Their temp depends on
system voltage. I had hard to make the LEDs usable for a range of 6-60 volts
without some tradeoff.
As long as the large chip isn’t getting hot you are OK.
From: Josh Baird
Sent: Wednesday, September 09, 2015 8:16 AM
To: af@afmug.com
Subject: Re: [AFMUG] GIGE-POE-APC Hot?
Yeah, it seems to be just the area around the LED. The connector is
not very hot at all.
On Wed, Sep 9, 2015 at 9:54 AM, Nate Burke <n...@blastcomm.com> wrote:
Or is it the area right by the LED's?
On 9/9/2015 8:52 AM, Ken Hohhof wrote:
The connector is hot? That can’t be right.
From: Josh Baird
Sent: Wednesday, September 09, 2015 8:43 AM
To: af@afmug.com
Subject: [AFMUG] GIGE-POE-APC Hot?
We just installed our first GIGE-POE-APC which is powering an
AF24, and noticed that it gets VERY hot. So hot that it almost instantly burns
your finger when you touch the green molding. For folks that have these
installed, is this normal?
It's ran fine for a few days, but this morning we we noticed that
the ethernet link on the AF24 was dropping (and coming back very quickly). I'm
not sure if it's related or not.
Josh
