Multiple 9VDC/250mA Power Supply

[Manchu]

I have 12 CMOS security cameras that require 6-9VDC/200-250mA each. I
have a power supply with an output of 13.7 VDC/2.7 A. I need to drop
the supply voltage and current and also protect the cameras from
possible power fluctuations. Any recommendations or possible
schematics out there on how to build this power supply? Is there any
web references? Any help would be greatly appreciated.

 

[John Fields]

I have 12 CMOS security cameras that require 6-9VDC/200-250mA each. I
have a power supply with an output of 13.7 VDC/2.7 A. I need to drop
the supply voltage and current and also protect the cameras from
possible power fluctuations. Any recommendations or possible
schematics out there on how to build this power supply? Is there any
web references? Any help would be greatly appreciated.

---
Bad idea.

If you have a security application and the single power supply fails,
then you no longer have a security system. Also, if a single camera
fails and, for some reason, pulls the single supply down or takes it
with it, then you also have no security system.

What I suggest you do is get twelve regulated 7.5V, 250mA power supplies
and connect one each to each of the cameras.

 

[Manchu]

---
Bad idea.

If you have a security application and the single power supply fails,
then you no longer have a security system. Also, if a single camera
fails and, for some reason, pulls the single supply down or takes it
with it, then you also have no security system.

What I suggest you do is get twelve regulated 7.5V, 250mA power supplies
and connect one each to each of the cameras.

John Thanks, I had considered this but hoped there may be a way around
this. The prospect of buying and placing 12 wall warts (and two power
strips) is not too inviting. I had considered (1) Placing the power
supply on an UPS (the UPS would be sized to the target duration, 45
Min) and (2) placing an inline fuse to each load to protect the other
cameras should one fail. I've seen some ideas on opposing Zener Diodes
to control fluctuations and a few "one box" commercial applications
for CCTV power but hoped I could do this as a project.