Any Electricians in the House? PSU Specifications..

efunc

Hi all,

I need a Power Supply to run a couple of security cameras. They each came with one with these specs:

SWITCHING POWER ADAPTER
MODEL: DSA-12PFG-12 FUK 120100
INPUT: 100-240V ~ 50/60Hz 0.5A
OUTPUT: 12V

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1A

My question is, if I want to purchase a new transformer or PSU to run BOTH cameras at the same time, is it sufficient just to get one at 12v 2A DC, or do I have to match the 0.5A input current, or does it have to change? Can anyone recommend a high quality one that will not pack up or run hot etc?

Thanks

grumbler

I am not an electrician, but I am pretty sure that you don't need to match 0.5A and it's a very approximate figure.
12V 2A is definitely fine for two.


Do the specifications not say anything about the input current of a camera or the power it consumes?

efunc

Thanks for that. I did call Ezviz who make the cameras but they just told me that running two cameras off one supply was not supported and they couldn't advise me further than that.

When I went on eBay to search for this particular adapter (for a spare) I found tons of other DVE Switching Adapters, many with similar specs (12v 1A) but with numerous different model numbers and slightly different input currents, like 0.3A, or the same 0.5A. It's begged the question why they make so many different ones if they just need one for each input voltage and output voltage and current. My assumption was that any of them would work, but I wanted to check.

keith969

These things are just switch mode power supplies and the input voltage is normally wide (100-240v typical). The input current is not really that important, its just given so you can get an idea of the power consumption of the psu when driving its rated output.

As to why there are so many different types - no idea but I guess they are just constantly changing/improving them.

Norman_Castle

efunc wrote: »

My question is, if I want to purchase a new transformer or PSU to run BOTH cameras at the same time, is it sufficient just to get one at 12v 2A DC, or do I have to match the 0.5A input current, or does it have to change? Can anyone recommend a high quality one that will not pack up or run hot etc?

As above, the input is what it draws from the mains supply which for these is irrelevant. To avoid failure over specify the output. For a 2A load get a 2.5A or larger output.

baldelectrician

Do you have any supplies from old routers- these are usually 12V above 1A?

GDB2222

You need to match the plug size, obviously. And, incredibly important, you need the plus on the plug to be positive.

shaun_from_Africa

If it was me, I would either stick to two separate power supplies or if using only one, I would put a 1 amp inline fuse on the feed to each camera.
That way, if one camera was to fail then hopefully the power to the 2nd camera wouldn't be cut and you would still have 1 working camera.

Heedtheadvice

DC Output voltage and current plus the connector physical size and polarity (centre contact positive as per the little diagram to the right of the output current 1A) are essential.


As written above over specifying the output current a bit will tend to help it run cooler.
Also the extra protection advised by Shaun is a good idea but the preference really is two supplies both for isolation and cooler running especially if you overspecify both outputs such as 2A each and ensure plenty of ventilation around them.


The Bald one has a good suggestion and provided the supplies meet the spec they need not be matched.

efunc

Thanks all for the very onformative replies, I've now identified some suitable PSUs.


I have one follow up question: I need an extension cable to situate one camera at some distance, between 6m and 10m from source. Can excessive cable length introduce greater resistance? And if so, can I compensate with the PSU?

GDB2222

If you use a mains extension cable, there’s no problem.