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-30°C rated 230VAC to 9V 1A supplies or 802.3at/af PoE splitters?

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Nominal Animal:
I've got some outdoors IP cameras above 68°N, sheltered from water and snow but not from the cold.  They lack PoE support, but consume less 0.8A at 9VDC.  I do have 230VAC mains available.

TP-Link TL-POE10R and other similar IEEE 802.3at/af PoE/PoE+ splitters I've found are only rated to 0°C/32°F (maybe to -10°C/14°F), but my cameras are rated to -30°C/-22°F.

I suspect my best bet is to get a Mean Well GST18E09-P1J wall wart, and shield it from the elements.  It is rated down to -30°C/-22°F, but is not IP-rated (so at best can be considered IP20).

The other option is to create a heated/insulated box, but that might overheat in the spring.

I like the idea of using a more easily available outdoors-rated mains to 12VDC 1A adapter, plus bodging in a linear regulator like Rohm BA90DD0T to regulate it to 9V.  However, making it stable for such a wide temperature range is black magic to me.  Maybe a couple of aluminium electrolytics in parallel?

Any suggestions?  I'd rather not spend too much money on these, as the cameras themselves aren't that expensive.  But perhaps someone here has already solved similar issues?

langwadt:
do you need "real" POE or can you just do the hack version and use the unused pair in 100Mbit?

I doubt  the 9V is that critical, the first think inside the camera is probably a voltage regulator

Nominal Animal:
There are some expensive industrial 802.3bt/at/af splitters like Aetek S69-220 that list -40°C to +75°C operating temperature, but at $150 a pop they're not worth it. direktronik.se makes an industrial 30W 12V 2.5A one, 20103219, that they promise -40°C to +85°C operating range; and at 30€ a pop it's on the border of my budget.. but they're sold out everywhere.


--- Quote from: langwadt on November 05, 2024, 11:13:41 pm ---do you need "real" POE or can you just do the hack version and use the unused pair in 100Mbit?
--- End quote ---
I can, yes.  While the mains power is nearby, the Ethernet cabling will be on the order of 15-20m, and I do intend to use good quality Cat6A/Cat7 S/FTP -40°C rated cables.  I think I can count on under 100Ω/km DC resistance.  Let's assume a generous 500mA current, which would correspond to 0.5V drop per 10m, wasting a quarter of a watt or so.  Perfectly acceptable... except I don't like the idea of 20m long cable without regulation, so I'm back at how to ensure the voltage at the camera stays within the safe limits.

I did find Silvertel Ag9712 and Ag9912M IEEE802.3af modules providing 12V 1A+ (15W) down to -40°C, only requiring PoE magjacks, a couple of full bridge rectifiers, ESD diode, 100µF+10µF+1.8µF+10µF filtering, a couple of 2kV 4.7nF (Y?) capacitors, and some ferrite beads for EMI suppression on the input.  This indicates this is definitely possible, even in a tiny form factor molded into resin.  But this is far outside my skill range and experience.  I'd have better success growing fur and moving to live in a nearby tree with binoculars.

I could just use an IP44 -40°C rated 12V 2A mains supply like EAN 6438195018625, possibly with a 5m extension lead, and be done with it, I suppose.  Making a small cylindrical linear regulator down to 9V encased in silicone and plastic at the camera power connector would be just about perfect, soothing all my fears and needs.


--- Quote from: langwadt on November 05, 2024, 11:13:41 pm ---I doubt  the 9V is that critical, the first think inside the camera is probably a voltage regulator
--- End quote ---
I'm currently testing Tapo C520WS cameras, and TP-Link is notorious for claiming nothing but their (0°C to +40°C non-IP-rated) 9V 0.8A supply will work.  If they only added IEEE 802.3bt/at/af support to Tapo cameras, they'd have a much better product in their hands.

Nominal Animal:
Seeed Studio makes a very interesting variant as well, SenseCAP PoE Splitter DC Jack 12V.  (Waveshare has a similar one, but only for 5V; the 5V 5A version is very interesting for small Linux servers like camera DVRs.)

Many Aliexpress sellers confuse "operating temperature" and "storage temperature".

And indeed, the proper industrial ones all seem to be using aluminium electrolytic capacitors.  I do believe the capacitors, and general thermal expansion/contraction (and difference between the coefficients for FR4 and electronic components, unless allowed for in the design), is what limits the minimum operational temperature.

TimFox:
If you need a simple thermostat to control a heater to keep your box above minimum temperature, "Klixon" snap-action thermal switches are available with standard setpoints down to -54o C = -65o F.

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