Anyone know a cheap supplier of 9vdc regulated power supplies?

[Pedro Popadopolous]

Any help greatly appreciated. 500mA needed

I want to run Camera's off these. Even better would be a single PSU that could run upto 4 cameras @ 500mA each

Thanks in advance

[John Weston]

Search for a switched mode power supply. There are many types available and several capable of the combined 2amps you require, and even more at single 500ma. You can get them for running from 90-240vAC mains or even 12vDC car supplies.

An example is:

(9v @ 2.6A, no 85-2942). I've not used these particular models so it's for information only

[jon sutton]

Part No. 494-5503 9v @ 3A £31

[Andrew Gabriel]

I doubt a camera really needs 500mA unless it's got some extra equipment such as lighting, screen wiper, etc. Might be worth measuring what the actual demand really is.

Also, a regulated power supply won't be as well regulated at the end of a long wire, which might be your situation if you have one supply feeding several dispersed cameras. Are you sure it needs a regulated supply? Cameras I've used all include the regulation locally, specifically so they can run on long supply wires. A single supply feeding over long wires to remote cameras could create ground loops, degrading the video quality.

CPC were doing 9V 1A power supplies for 99p for many months, but it looks like they have finally got rid of them all now as I can't find them on their web pages. I have found small PSU's I've needed for various things by rummaging in a bin full of them in Cash Converters, for £1 each.

I would be slightly weary of a switched mode PSU for this application, in case the switching frequency manages to break through into the video output, where it could cause bad visual interference.

[John Weston]

Valid point - but I don't have a problem with the one I use in a similar application (A Maplin purchase). I think the main message is that switched mode or linear, don't get one that exactly matches the load you need. Better to over-specify it so it isn't operating near its designed limits. That keeps any noise effects to an absolute minimum, if they are there at all.