High current 5 volt filtered DC for powering multiple cameras - Page 1
Forum section: electronics / projects

author: SWBCA
author_rank: Newbie
timestamp: October 28, 2024, 12:43:39 pm
content: We are building a garage and want to use a single 5v power supply for several security cameras that come with 5v usb power blocks. Rather than installing 120 volt outlets for each security camera, I would prefer to prewire the garage with 14 guage EC3 twisted cable attached to a single 5 volt DC power supply for 4 or 5 cameras. I can't find any 5 volt DC power supply devices that claim to be filtered so there isn't 60Hz line noise passed on to the 5volt supply.

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 28, 2024, 01:16:28 pm
content: Quote from: SWBCA on October 28, 2024, 12:43:39 pmPossibly, manufacturers don't claim it because an output is filtered by design. The question is only how good it is filtered.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: October 28, 2024, 01:18:07 pm
content: Mouser stock a range of 5V power supplies, one example is this one (they are based in the USA):https://www.mouser.com/ProductDetail/Cosel/PDA30F-5-N?qs=ZcfC38r4Pot3vFxYe8xeJg%3D%3DSJ

author: Manul
author_rank: Super Contributor
timestamp: October 28, 2024, 06:26:21 pm
content: All switching supplies will have negligible mains ripple at the output. There will be some high frequency switching noise though (in your case - unlikely to be a problem). The biggest worries are these:1. Voltage drop;Choose your wire and it's length accordingly.2. Inductance of the wire;Long wire, lots of inductance. Transient response might have high overshoots and might fry the cameras. We don't know if cameras have built in protection for that. If in doubt, general advice would be to add small electrolytic capacitor and 5V TVS near every camera.

author: Randy222
author_rank: Frequent Contributor
timestamp: October 28, 2024, 06:53:25 pm
content: Does the solution need UPS power?I would run 24dc as source, run your wires (perhaps not even needed 14ga) , then dc-dc down to 5vdc at each cam location, and maybe add a filtering cap on output of dc-dc converter.If you need UPS, two 12v marine batts is an easy solution.And btw, there's plenty of switching PSU's on the net, and not expensive. 5v 30A is common, overlay frequency will be way higher than 60Hz, and perhaps way smaller.If you ever swap out a cam to say a 9v cam, then just swap out the dc-dc to accomodate.

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 28, 2024, 07:31:26 pm
content: There are several ways to skin a cat, and as such when you ask the question, you'll receive several differing answers.Personally, I like Randy222's higher-source voltage the best. It could be 24V source voltage as suggested, or it could be 12V source voltage.Cameras may not consume much during regular operation. But at night, when the IR LEDs light up, the current consumption increases significantly.And of course, if the camera has a tilt and pan operation, the consumption will increase even further.In theses circumstances, to avoid voltage drops on long runs which could cause nuisance resets, it is better to run at a higher source voltage.

author: Someone
author_rank: Super Contributor
timestamp: October 29, 2024, 06:59:06 am
content: Quote from: Manul on October 28, 2024, 06:26:21 pmNot true, many brand name and well specified switching supplies have more mains ripple than switching ripple or noise when loaded.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 29, 2024, 07:47:53 am
content: Quote from: SWBCA on October 28, 2024, 12:43:39 pmYou are into less-chartered waters there.How much current do you need for each camera ? IR LED arrays can swallow quite a bit.More common might be to combine LED 12V switchers, with USB charger modules for cars, both made in very large volumes.You run 12V (9-24V) on the (lighter & cheaper) cables and each node drops that locally to 5V

author: Siwastaja
author_rank: Super Contributor
timestamp: October 29, 2024, 08:48:11 am
content: What makes you think "60Hz line noise", whatever that means, is a problem? I'm pretty certain USB-powered cameras are fine with almost any legally available 5V switch mode supply. Just make sure the wire gauge is sufficient to avoid voltage drops, and I mean if the wires are long you might need excessively heavy wire gauge which costs a lot of money: local power supplies is probably a better idea because of this.

author: Manul
author_rank: Super Contributor
timestamp: October 29, 2024, 10:59:27 am
content: Quote from: Someone on October 29, 2024, 06:59:06 amCan you elaborate? I'm wondering what were these supplies and why feedback loop was not compensating for such slow input ripple? So what loop BW do they have? In that case I expect such supply to also have a terrible load transient response. Or are you talking about driving a supply near it's current limit, when it may not have room to regulate?

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 30, 2024, 12:36:28 am
content: Quote from: Manul on October 29, 2024, 10:59:27 amIt does compensate, but it does not entirely remove it.See this link for images :https://meanwellpowersupplies.com/faq/what-is-ripple-noise-how-to-measure-it/

author: Someone
author_rank: Super Contributor
timestamp: October 30, 2024, 06:24:00 am
content: Quote from: Manul on October 29, 2024, 10:59:27 amYes, most "brick" type switching supplies have terrible load performance 5%, 10%, completely "normal". The mains ripple comes through mostly because of cost cutting in the large high voltage link/primary capacitor so grows with total load (line regulation does not vary massively with load).