Any Electricians in the House? PSU Specifications..

grumbler

Can excessive cable length introduce greater resistance?

Of course. For long USB charging cables it's a common problem.

Resistance is directly proportional to the length.

However, if the current is low, extra resistance will change the voltage very little.

It's unlikely to be a problem, but worth checking how the camera works with the extension cable before laying it.

can I compensate with the PSU

How? By increasing the voltage? I wouldn't do this in general and especially if you have a common PSU for two cameras. If it's really a problem, use a thicker wire (resistance is inversly proportional to the crossection area) or use two PSUs and fix them close to the cameras.

efunc

Thanks. It's the 12v cable I intend to extend. One needs to be 7m or so. It's easier to find 10m extensions but I wondered if I should try to avoid the extra 3m and just buy bare cable and splice a socket on it rather than introduce unnecessary resistance. Also, it's hard to tell what's good quality copper cable and what cable might have greater resistance just from the descriptions on Amazon or eBay. I figured the shorter the better to be safe. However I'm guessing 10m and even 20m extenders aren't uncommon for CCTV.

coffeehound

What are the actual specs for the cameras in terms of current / wattage?

efunc

They are EZVIZ C3W (ezGuard) CS-CV310-A0-1B2WFR 1080P Outdoor Security Cameras. I'll try and dig out the full specs later if I can, but they are 12v DC and the PSU is rated at 1A.

efunc

The manual provides the following info:

Power Supply: DC 12V±10%
Power Consumption: Max. 6W

efunc

Does this sort of thing look decent quality? 12v 2.5A: https://www.ebay.co.uk/itm/LED-Driver-Transformer-IP67-Waterproof-Outdoor-Power-Supply-240V-DC12V-24V/232816015255?var=532327397216

coffeehound

efunc wrote: »

The manual provides the following info:

Power Supply: DC 12V±10%
Power Consumption: Max. 6W

Thanks -- so maximum current drain is only half an amp at 12 volts.

thorganby

efunc wrote: »

The manual provides the following info:

Power Supply: DC 12V±10%
Power Consumption: Max. 6W

Each camera draws a maximum of 0.5A then.

efunc wrote: »

Does this sort of thing look decent quality? 12v 2.5A: https://www.ebay.co.uk/itm/LED-Driver-Transformer-IP67-Waterproof-Outdoor-Power-Supply-240V-DC12V-24V/232816015255?var=532327397216

You do not need a 2.5A PSU and although that may work, it is designed to drive LED's so it may not have a clean enough output for your cameras i.e. may produce noise on the image.

GDB2222

This would work:
https://www.amazon.co.uk/BENSN-Adapter-Appliances-External-Keyboards/dp/B07JY9FBLR

efunc

Great, thanks. That looks like a good one, I'll probably order it.


Ironically I've bought 4 of these cameras but only just discovered they may not be supported by my Synology NAS other than as generic IP cameras. For some reason I thought I read somewhere that they were on the supported camera list. Oh well. I've now got the lovely choice of just using them with the horrible EZVIZ app, using them as basic cameras with my Synology NAS, getting another dedicated EZVIZ NVR to run them, or dumping them and getting Reolink ones instead. Nothing's ever simple..