On Sat, 11 Feb 2023 07:44:37 -0800, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:
>On Sat, 11 Feb 2023 07:10:23 GMT, Jan Panteltje <alien@comet.invalid>
>wrote:
>
>>On a sunny day (Fri, 10 Feb 2023 13:16:24 -0800) it happened John Larkin
>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>><5icduh5ftrih8qfb1u1s398dah9ntt9671@4ax.com>:
>>
>>>Looks like a lot of people make a SIP-packaged PoE power module.
>>>
>>>https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>>>
>>>and they look to be approximately drop-in compatible. They get one or
>>>two pairs of DC from the ethernet connector and make isolated DC out,
>>>from 3.3 to 24 volts in various versions.
>>>
>>>So it could be a plug-in option for a little box that otherwise runs
>>>from a 24 volt wart.
>>>
>>>Price is roughly $10. The cheapest Alibaba unit is around $3!
>>
>>
>>What do you do when one fails a few years from now?
>>Buy a hundred up front?
>
>Or a thousand. Or design for multiple sources; there seem to be
>several. Or untimately make our own as a last resort.
>
>I like the SIP package. We could offer PoE as an option. It wouldn't
>take much board space.
Test 1 2 3
Reply by Lasse Langwadt Christensen●February 11, 20232023-02-11
fredag den 10. februar 2023 kl. 22.16.38 UTC+1 skrev John Larkin:
> Looks like a lot of people make a SIP-packaged PoE power module.
>
> https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>
> and they look to be approximately drop-in compatible. They get one or
> two pairs of DC from the ethernet connector and make isolated DC out,
> from 3.3 to 24 volts in various versions.
>
> So it could be a plug-in option for a little box that otherwise runs
> from a 24 volt wart.
>
> Price is roughly $10. The cheapest Alibaba unit is around $3!
> It's a fairly wide-range DC/DC converter, but at least one (Ubiquiti) PoE injector
> in my junk box sources 24VDC, and that's out of its (36V-57V) range.
> These specs are reminiscent of the telecom style converters used with
> 48V systems.
Sadly, there are many things that "deliver power over an ethernet cable"
that are erroneously labeled as "PoE".
The actual standards are pretty comprehensive and tend to cover the
"real" use cases, well -- including protecting against non-PD devices
being connected to a PoE-enabled drop.
Increasingly, I see people moving away from midspan injectors to endspan
support.
It's not hard to design a universal PD configuration that will tolerate
both A and B configurations as well as polarity independence. (This
because the PSE has the final word on how it will supply power) And,
develop the supplies that you *actually* need in your PD.
Reply by Jan Panteltje●February 11, 20232023-02-11
On a sunny day (Fri, 10 Feb 2023 13:16:24 -0800) it happened John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote in
<5icduh5ftrih8qfb1u1s398dah9ntt9671@4ax.com>:
>Looks like a lot of people make a SIP-packaged PoE power module.
>
>https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>
>and they look to be approximately drop-in compatible. They get one or
>two pairs of DC from the ethernet connector and make isolated DC out,
>from 3.3 to 24 volts in various versions.
>
>So it could be a plug-in option for a little box that otherwise runs
>from a 24 volt wart.
>
>Price is roughly $10. The cheapest Alibaba unit is around $3!
What do you do when one fails a few years from now?
Buy a hundred up front?
Reply by John Larkin●February 10, 20232023-02-10
On Sat, 11 Feb 2023 10:39:03 +1100, Clifford Heath
<no.spam@please.net> wrote:
>On 11/02/23 08:16, John Larkin wrote:
>> Looks like a lot of people make a SIP-packaged PoE power module.
>>
>> https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>>
>> and they look to be approximately drop-in compatible. They get one or
>> two pairs of DC from the ethernet connector and make isolated DC out,
>> from 3.3 to 24 volts in various versions.
>>
>> So it could be a plug-in option for a little box that otherwise runs
>> from a 24 volt wart.
>>
>> Price is roughly $10. The cheapest Alibaba unit is around $3!
>
>DIY output filtering, and no RF noise or EMI specifications.
Adding some beads and caps would be no big deal. If I allow optional
wart DC power, they'd be there anyhow.
>No
>shielding is apparent either.
Well, it is a bare PCB. I'll put it on a board in an aluminum box.
Reply by Clifford Heath●February 10, 20232023-02-10
On 11/02/23 08:16, John Larkin wrote:
> Looks like a lot of people make a SIP-packaged PoE power module.
>
> https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>
> and they look to be approximately drop-in compatible. They get one or
> two pairs of DC from the ethernet connector and make isolated DC out,
> from 3.3 to 24 volts in various versions.
>
> So it could be a plug-in option for a little box that otherwise runs
> from a 24 volt wart.
>
> Price is roughly $10. The cheapest Alibaba unit is around $3!
DIY output filtering, and no RF noise or EMI specifications. No
shielding is apparent either.
Reply by whit3rd●February 10, 20232023-02-10
On Friday, February 10, 2023 at 1:16:38 PM UTC-8, John Larkin wrote:
> Looks like a lot of people make a SIP-packaged PoE power module.
>
> https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
>
> and they look to be approximately drop-in compatible. They get one or
> two pairs of DC from the ethernet connector and make isolated DC out,
> from 3.3 to 24 volts in various versions.
>
> So it could be a plug-in option for a little box that otherwise runs
> from a 24 volt wart.
>
> Price is roughly $10. The cheapest Alibaba unit is around $3!
It's a fairly wide-range DC/DC converter, but at least one (Ubiquiti) PoE injector
in my junk box sources 24VDC, and that's out of its (36V-57V) range.
These specs are reminiscent of the telecom style converters used with
48V systems.
Reply by John Larkin●February 10, 20232023-02-10
Looks like a lot of people make a SIP-packaged PoE power module.
https://www.mouser.com/ProductDetail/Silvertel/Ag9712-2BR?qs=OlC7AqGiEDmgbLGLmzziyA%3D%3D
and they look to be approximately drop-in compatible. They get one or
two pairs of DC from the ethernet connector and make isolated DC out,
from 3.3 to 24 volts in various versions.
So it could be a plug-in option for a little box that otherwise runs
from a 24 volt wart.
Price is roughly $10. The cheapest Alibaba unit is around $3!