Hello,
i have 3 Amazon Blink cameras, each 5V 1A.
Can I power all of them using once PSU - 5V 6A?

Thanks

 

Hello,
i have 3 Amazon Blink cameras, each 5V 1A.
Can I power all of them using once PSU - 5V 6A?

Thanks

Why not?
If each camera takes 1 A and the PSU can supply 6 A, you have 3 A to spare.

 

@MrChips i think i was told some time ago,
that if u have for example 12V 5A, and two different devices lets say 12V 1.4A, 12V 1A ... its not a good idea to connect them both on one PSU.

thanks

 

@MrChips i think i was told some time ago,
that if u have for example 12V 5A, and two different devices lets say 12V 1.4A, 12V 1A ... its not a good idea to connect them both on one PSU.

thanks

I don’t know where you got that misinformation.

If all the devices require the same voltage then you can drive them from the same PSU. It would have to be a very special case where this was not recommended.

 

@MrChips i think here

https://forum.allaboutcircuits.com/threads/power-sockets-dc-devices.207935/post-2000433
https://forum.allaboutcircuits.com/threads/power-sockets-dc-devices.207935/post-2000436
https://forum.allaboutcircuits.com/threads/power-sockets-dc-devices.207935/post-2001830

 

i think i was told some time ago,
that if u have for example 12V 5A, and two different devices lets say 12V 1.4A, 12V 1A ... its not a good idea to connect them both on one PSU.

A statement saying it must/will work or might/won't work needs to be taken with a grain of salt.

You say the cameras draw a maximum of 1A. That means they might not ever draw that, or anywhere near that, under actual operation.

If they actually draw 1A and you feed them with a long, small diameter wire, there could be voltage drop that could affect operation. I had this situation for a 12V security camera with a long-ish cable that carried video and power (in separate wires). The power cable was such a small diameter that there was a couple volt drop at the camera that made it unreliable. I ended up using a dedicated 14.4V supply for the camera in question.

You could use a single 5V/6A supply for the 3 5V/1A cameras as long as voltage drop in the lines you run to them don't cause a voltage drop large enough to affect operation. Most would probably assume that you knew that...

 

You could use a single 5V/6A supply for the 3 5V/1A cameras as long as voltage drop in the lines you run to them don't cause a voltage drop large enough to affect operation. Most would probably assume that you knew that...

@dl324
thanks, yes i am aware of the Voltage drop thats why i went for 5V psu from meanwell where u can set it to 5.5V and using wire for calculated distance at the end u have 4.9-5V.

So does it mean that i can attach only similar 5V devices on that PSU ie 3x Camares, or i can attach also different 5V device?

Assuming the total sum of max A (of all devices) < PSU max A.

thanks

 

There are two concerns mentioned in those posts:

1) Supply noise and instability
If you have a device that draws a lot of current on initial turn on or while switching a large load, you might experience brown outs on the supply rail. A good quality power supply must be able to supply temporary surge current.

A device could conceivably generate a lot of electrical noise that can propagate through the power rails. Every device should provide its own internal EMI filters. For example, all automotive 12 V electronics must be designed to suppress EMI coming from the automobile’s ignition system.

2) Isolation
Conceivably, some devices require positive voltage on the PSU center pin while others require negative voltage. This is not a problem if there are no interconnections between devices. If devices share a common ground, you need to check that the power adapter and signal connections are compatible.

Note: Not all wall adapters are floating. You need to check for compatibility between devices and power adapters if the adapters are not isolated.

 

i am aware of the Voltage drop thats why i went for 5V psu from meanwell where u can set it to 5.5V and using wire for calculated distance at the end u have 4.9-5V.

The problem with using an adjustable power supply to compensate for voltage drop is that all of the devices will use that same voltage. If the wire lengths are different, then each device will have a different voltage drop.

Also note that the individual 5V devices should have a voltage tolerance.

So does it mean that i can attach only similar 5V devices on that PSU ie 3x Camares, or i can attach also different 5V device?

Assuming total sum of max A (of all devices) < PSU max A.

Any combination of 5V devices can be powered from the same power supply as long as you consider voltage drops in the individual power lines and don't exceed the current rating of the supply.

If one or more of the devices feed noise onto the power supply, that could be problematic.

 

In many cases, devices have internal voltage regulators.
Hence voltage loss on long cables are not a problem.

 

2) Isolation
Conceivably, some devices require positive voltage on the PSU center pin while others require negative voltage. This is not a problem if there are no interconnections between devices. If devices share a common ground, you need to check that the power adapter and signal connections are compatible.

Thats what i do not understand.

whats PSU center pin? I have PSU which has +/- ... and i create separate wires to the endpoint devices ; so +/- is provided correctly.

what do u mean by interconnections between devices?

IF u have one PSU with +/- ... and u attach 3 devices to it ... all will share same ground (-) from that PSU?

 

The problem with using an adjustable power supply to compensate for voltage drop is that all of the devices will use that same voltage. If the wire lengths are different, then each device will have a different voltage drop.

yes thats okay, and i know that its limitation parameter.

If one or more of the devices feed noise onto the power supply, that could be problematic.

ie if devices is low cost it can feed noise onto the PSU and affect all other?

 

If you have three identical devices, connect +ve to PSU +ve.
Connect -ve to PSU -ve.

 

If you have three identical devices, connect +ve to PSU +ve.
Connect -ve to PSU -ve.

yes... thats how it should be done.


But question was more generic ... if lets say some other 5V can be added on the same PSU.

 

Hello,

Do you mean to add an other power source to the existing powersource?

Bertus

 

no i meant another Endpoint device... which consumes 5V.

 

I have a home security system that features 12V cameras that are wired. Each camera is powered from a dedicated wall wart (WW). To save 110VAC plug space I found a larger 12V supply that had ample power to run all the cameras. However, when I ran all four cameras off a single 12V supply they still worked but the video quality was horrible. Not sure how to describe it but imagine 50 glass rods (round rods) all lined up across the screen from bottom to top, then look at the image behind the rods. The rods act like lens's and distort the video. Only when each camera was powered via its own source did it work properly. I even tried applying filter caps to smooth out whatever was causing the ripples but even that had no effect. To this day I don't know why it does that - but it does. Four cameras on a single supply doesn't work well for me. No idea why!

 

I have a home security system that features 12V cameras that are wired. Each camera is powered from a dedicated wall wart (WW). To save 110VAC plug space I found a larger 12V supply that had ample power to run all the cameras. However, when I ran all four cameras off a single 12V supply they still worked but the video quality was horrible. Not sure how to describe it but imagine 50 glass rods (round rods) all lined up across the screen from bottom to top, then look at the image behind the rods. The rods act like lens's and distort the video. Only when each camera was powered via its own source did it work properly. I even tried applying filter caps to smooth out whatever was causing the ripples but even that had no effect. To this day I don't know why it does that - but it does. Four cameras on a single supply doesn't work well for me. No idea why!

@Tonyr1084 assuming the PSU max A was still higher that sum (each_camera max A)


Its weird bc it can imply that in case one attach other devices like Sensors etc... it might affect them?

Wondering if such a devices like that have 2 psu for each USB port or its also 1 PSU output shared between 2 devices?
https://www.se.com/ie/en/product/GG...-charger-2-x-usb-3-1-a-stainless-steel-white/

 

Wondering if such a devices like that have 2 psu for each USB port or its also 1 PSU output shared between 2 devices?

Typically devices with 2 USB's have one at 1A and the other at 2.5A. Or something like that. I have plenty of those. I'd imagine that they may have common parts and dedicated parts. The parts that are dedicated to 2.5A are likely isolated from the 1A. But keep in mind, those are for charging. Not necessarily for powering electronics.

assuming the PSU max A was still higher that sum (each_camera max A)

The camera draw daytime color draw was less than 2A. Night time black/white w/infrared illumination probably not more than 3A. The supply used was able to power a single camera with no interference. But as soon as I plugged a second camera into it there was interference. The supply total power output was 20A. Almost 50% bigger than the expected draw. But even in daytime without the IR the picture was distorted. Didn't even try to see what they did at night. And remember, the distortion was there with two cameras connected.

Just to be clear: the power leads were connected to common ports. Four positive ports, four negative ports. All four ports (+&-) were common.

 

But keep in mind, those are for charging. Not necessarily for powering electronics.

Whats the difference? thanks