power supply questions

Hi Christopher, Your total load at 12 Volts is approx 2.5 Amp (Including extra load if PIRs' are being activated). My personal choice would be a 12 Volt 5Amp Fused, Regulated Supply by any of the good Manufacturers. If you are using mains operated cctv equipment there is little point in having battery back-up in the PSU

Thanks for the quick response. My cameras are IP with POE that run to the computer room that happens to have good battery backup, but our power here is quite stable and I don't anticipate theft during one of the rare outages, so I probably won't bother with battery backup on the PSU. I should have asked, what gauge wire for the IR Illuminator? What guage wire for the PIRs and PIR relay triggers?

Also, you could help my PSU google search if you recommend one or two good brands / models.

Best, Christopher

I like the Altronix line of Power supplies along with stealth products

I found a wire gauge calculator on the net. The calculator only had VAC. Does 12VAC require a similar gauge as 12VDC? Here are the calculations, assuming 12VAC is the same as 12VDC.

IR Illuminator - 12 VDC, 75', 25 W

10% loss recommends 14 gauge 5% loss recommends 12 gauge

So, I'm guessing 12 gauge stranded for the 12 VDC 25W IR Illuminator would suffice, is that correct?

For the Crow Daredevil PIRs and triggers, I'm guessing 22 gauge is more than adequate, correct?

Also, the Illuminator will take either AC or DC, while the PIRs are DC only. Is there a benefit to using 12 VAC for the Illuminator? Are there PSUs that provide both 12VAC and 12VDC? Or, should I just keep it simple and get one

12VDC supply to run both the Illuminator and the PIRs.

Best, Christopher

Thanks, I really appreciate all the help.

Best, Christopher

From Wiki - "For long-distance distribution, HVDC systems are less expensive and suffer lower electrical losses. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may be warranted where other benefits of direct current links are useful."

Best, Christopher