Vlock power connection question.

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ricardo marty

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Vlock power connection question.

PostFri Jun 07, 2019 5:13 pm

I just got a camvate vlock plate to use with my bp4k. I am using a Sony battery plate for two np=f970 batteries.

The vlock has the following outputs.

1 12v barrel male
1- 7,2 barrel male
1- 14.4 dtap
1-USB 5v
and the battery plate has max 50w dtap

Am I correct if i use the 14.4 dtap for the camera and the 7.2 for the evf. or connection or the dc 2.5 6-18v?

what are the other outputs for?


Thank you

Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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Denny Smith

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Re: Vlock power connection question.

PostFri Jun 07, 2019 5:55 pm

Yes, use the DTap for the camera, but be careful about connecting a monitor to then12VDc port, as this can create a ground loop and fry a hdmi port. I power my monitor from its own battery, which is a Canon LP E6 and lasts in the Monitor quite long. Yiu need the bigger battery on the camera for longer takes.
See Sijan’s Battery thread for details on ground loops.
Cheers
Denny Smith
SHA Productions
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ricardo marty

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Re: Vlock power connection question.

PostFri Jun 07, 2019 6:50 pm

Denny Smith wrote:Yes, use the DTap for the camera, but be careful about connecting a monitor to then12VDc port, as this can create a ground loop and fry a hdmi port. I power my monitor from its own battery, which is a Canon LP E6 and lasts in the Monitor quite long. Yiu need the bigger battery on the camera for longer takes.
See Sijan’s Battery thread for details on ground loops.
Cheers


I was planning to connect the evf to the 7. v. Would this also create potential problems?

Would I have the same problem I use a dummy for the camera to power everthing?

Thanbks

Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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Dmitry Shijan

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Re: Vlock power connection question.

PostFri Jun 07, 2019 8:02 pm

The nature of this problem is not fully understandable yet. There are a summary of possible reasons that can burn HDMI port. Ground loop connection + electrostatic discharge spark + low quality HDMI cable ground insulation + possible lack of electrostatic discharge protection circuit for HDMI chip in BM cameras.
There are a lot of threads about SDI/HDMI output broken on BM cameras in similar situation:

Totally confused. Faulty Tilta plate fried EVF? http://www.bmcuser.com/showthread.php?8440
Blew the SDI port on my BMCC again... http://bmcuser.com/showthread.php?9923
Tascam DR60D ground loop? http://bmcuser.com/showthread.php?7859
SDI burnout/rolling noise issue BMCC 2.5k EF https://forum.blackmagicdesign.com/viewtopic.php?t=22659
MY SDI input on my BMCC Stop Working https://forum.blackmagicdesign.com/viewtopic.php?t=25621
BMCC SDI problem https://forum.blackmagicdesign.com/viewtopic.php?t=16745
HDMI port on my BMMCC don't works anymore http://bmcuser.com/showthread.php?21004 ... post254391



This is also a quote i got from BMD Support:

Potential causes of SDI failure and how to minimize them.

Isolated Grounds
Isolated grounds may be implemented on a battery plate for safety reasons to allow for isolation between individual devices powered by the plate.
If two devices are connected to individual power connectors AND also have an additional cable between them, there could be the chance of voltage offset.
For example, with an EVF setup, where the camera is on one battery plate power connector, the EVF is on a second plate power connector, and an SDI cable is connected between the devices. Assuming that the SDI connector is internally connected directly to the power negative on each device (chassis ground), then the circuit design will be utilizing the SDI cable shield to provide the common ground connection between the two power supplies. If either the camera or the EVF DO NOT have their SDI shield conductor connected directly to chassis ground, if the SDI cable length is sufficiently long or of poor quality, then the shield in the SDI cable will act as a low-value resistor, and a current will flow through the cable shield between the two devices. You could expect a potential difference measured from one supply's ground to the other.
If the camera and monitor are using either two independent power sources or two power sources on the battery plate where the D-Tap connector may be connected directly to the battery terminals it may have a different negative potential to that of the rest of the power connectors. Ground connection contact bounce may occur and there could be a chance of damaging SDI ports. Contact bounce may also cause all manner of transient voltage spikes to go through the equipment and could cause unforeseen issues.

Prevention
If you have a battery plate with isolated ground supplies, it is recommended to only use it if both the camera and the EVF were powered from the exact same power connector. This can be achieved by plugging a D-Tap multi-tap into the plate D-Tap connector, then connect individual D-Tap cables from the multi-tap to the camera and EVF. That way they are using a common negative connection, with no chance for floating voltage potential variations.
If avoidable SDI interfaces should not be hot-plugged. When setting up or dismantling camera setups make sure that all devices are completely turned off before making any connections to any of the device's inputs or outputs, and any batteries that can be, should removed or disconnected since some battery outlets are always powered.

Electrostatic Discharge (ESD)
This can occur randomly at anytime and can be caused by clothing, packaging, plastics and atmospheric conditions. If you are carrying even a small static charge, you could possible damage sensitive electronic components.
Whilst BNC connectors are designed to minimise contact with the center conductor, if you inadvertently touch near the center contact you could cause a static discharge.

Prevention
The same static prevention measures used when handling sensitive electronic components should be employed when handling video production equipment
As a matter of course discharge yourself when handling a device by touching any large metal object next to you such as a metal table or metal stand or water pipe etc.
SSD drives and the SATA interfaces also do not have high ESD protection.
Always keep any antistatic bags that the SSD drive came in, and always use them for transport and storage of the drive. Use care and try to never touch the drive contacts. SDI ports may also quite sensitive to ESD so static safety precautions should also be implemented when connecting or removing cables.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
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ricardo marty

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Re: Vlock power connection question.

PostFri Jun 07, 2019 8:50 pm

Dmitry Shijan wrote:
Prevention
If you have a battery plate with isolated ground supplies, it is recommended to only use it if both the camera and the EVF were powered from the exact same power connector. This can be achieved by plugging a D-Tap multi-tap into the plate D-Tap connector, then connect individual D-Tap cables from the multi-tap to the camera and EVF. That way they are using a common negative connection, with no chance for floating voltage potential variations.
If avoidable SDI interfaces should not be hot-plugged. When setting up or dismantling camera setups make sure that all devices are completely turned off before making any connections to any of the device's inputs or outputs, and any batteries that can be, should removed or disconnected since some battery outlets are always powered.
[/quote]


This is for a bmpcc4k

So you say that if I have both the camera and evf connected with different cables to the vlock, then I should have no problem. Yes? The evf power input says (dc 2.5, 6.8 - 18 v)

What if I get a dummy battery and connect it to the cameras power input? cameras

Thank You


Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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Dmitry Shijan

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Re: Vlock power connection question.

PostFri Jun 07, 2019 9:16 pm

1. Any additional DC-DC power regulator or step down converter between battery and device will waste about 10% of battery capacity during conversion. So when possible you better use direct 14.8V output from the v-mount battery to device to increase battery working time. 14.8V or 14.4V is average battery voltage mark. In reality battery outputs in range from 16.8 (full charged) to 10-12V (full discharged).
2. Also any additional DC-DC power regulator or step down converter between battery and device probably increases the risk of damage and also adds additional electric signal pollution.
3. There is no any world in BM response about this, but any device (camera or evf) have it's own internal DC-DC power regulator which outputs different voltage to different device, so even if you power camera and EVF directly from battery, you still have potential ground loop problem explained in the video i post earlier.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
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ricardo marty

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Re: Vlock power connection question.

PostFri Jun 07, 2019 9:37 pm

Dmitry Shijan wrote:1. Any additional DC-DC power regulator or step down converter between battery and device will waste about 10% of battery capacity during conversion. So when possible you better use direct 14.8V output from the v-mount battery to device to increase battery working time. 14.8V or 14.4V is average battery voltage mark. In reality battery outputs in range from 16.8 (full charged) to 10-12V (full discharged).
2. Also any additional DC-DC power regulator or step down converter between battery and device probably increases the risk of damage and also adds additional electric signal pollution.
3. There is no any world in BM response about this, but any device (camera or evf) have it's own internal DC-DC power regulator which outputs different voltage to different device, so even if you power camera and EVF directly from battery, you still have potential ground loop problem explained in the video i post earlier.


Ok thanks

Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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Re: Vlock power connection question.

PostFri Jun 07, 2019 10:14 pm

is this the same with an Ursa mini pro? Meaning, should I not power my camera and my external monitor using the same v mount battery? currently running the v lock battery on the plate an a D Tap to DC cor straight to my monitor.
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Dmitry Shijan

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Re: Vlock power connection question.

PostFri Jun 07, 2019 10:39 pm

If you use ground looped connection it don't means that it should burn HDMI chip momentary once you turn camera on. The problem is not fully understandable yet and probably consists of many factors. My personal guess is that damage may be caused due ground loop combined with electrostatic discharge and low quality HDMI cable. These are exact factors i observed when i got HDMI port damage in my camera.
- Earlier during few years when i use separate monitor battery i also got few electrostatic discharge sparks to the camera but don't have any problem or damage.
- Also all this time i used cheap angle HDMI cable without any problems. But when i measured voltage between grounds it appears cable produce 0.3V voltage leak. Other better quality cables gives me 0 to 0.001V voltage leak. So i decide that cable itself may be part of problem source as well.

A lot of people use ground looped connection without problem, but some people got HDMI/SDI ports damage and there is still no any clear logical scientific explanation for this. Only guesses and theory... I wish someone could explain to us things further from scientific point of view.
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ricardo marty

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Re: Vlock power connection question.

PostSat Jun 08, 2019 1:02 am

Australian Image wrote:I case you're curious, this is my battery setup:

bmpcc (116).jpg



What do you have connected to the vlock?


Ricardo Marty
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Dmitry Shijan

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Re: Vlock power connection question.

PostSat Jun 08, 2019 1:03 pm

Here is another happy ground loop user story from YouTube comments. But regarding Pocket4K and Ursas - there is no any info if BM add HDMI chip protection to this cameras or keep things the same.
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ricardo marty

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Re: Vlock power connection question.

PostSat Jun 08, 2019 4:28 pm

Dmitry Shijan wrote:Here is another happy ground loop user story from YouTube comments. But regarding Pocket4K and Ursas - there is no any info if BM add HDMI chip protection to this cameras or keep things the same.



So what is the process and cost of fixing the damage?
Dmitry Shijan wrote:Here is another happy ground loop user story from YouTube comments. But regarding Pocket4K and Ursas - there is no any info if BM add HDMI chip protection to this cameras or keep things the same.


What is the process and cost of fixing this damage.

Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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ricardo marty

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Re: Vlock power connection question.

PostSat Jun 08, 2019 4:31 pm

Australian Image wrote:Camera, monitor, audio recorder, Tilta Nucleus Nano hand controller and motor. I bought some 5.5mm x 2.1mm barrel plugs with tail and have made some extensions with single or double outlets on the other end so that I can power the accessories.


Looks good, what is your battery v? That's what I wanted to do but know I'm not sure. BTW where can I get that cylinder thing on the rear of the rig? I assume its for carrying your rig?


Ricardo Marty
Resolve Studio 17, Lenovo 7i15, i7-10750H Processor, 6 Cores, Nvidia 2060 6Gb, 16Gb ram, 512 nvme sd. Sony FS700R, Bmp4k, Sony A6600. Focusrite ableton
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Denny Smith

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Re: Vlock power connection question.

PostSat Jun 08, 2019 5:40 pm

AbdoulUK wrote:is this the same with an Ursa mini pro? Meaning, should I not power my camera and my external monitor using the same v mount battery? currently running the v lock battery on the plate an a D Tap to DC cor straight to my monitor.


No, the Ursa Mini has a 12-VDC out (front 4-pin XLR) and an isolated DTap on the batter mounting plate, that is regulated from the camera’s DC/DC power board. Just always shut down the camera when making power and SDI connections, and yiu should be fine. I use these camera power ports for connecting a EVF to front and a LCD monitor to the rear connection. The battery connects to the BMD Camera V-Lock plate.
Cheers
Denny Smith
SHA Productions
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Re: Vlock power connection question.

PostFri Mar 06, 2020 5:06 pm

Hey all - sorry to resurrect a thread from the dead, but I figured instead of making a new one, maybe I could get some help here and possibly continue the conversation.

Could this possibly be a fix for the issues that we’re running into?

https://rencherindustries.com/products/ ... 5088218215

This provides two regulated 12V D-Taps...
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Dmitry Shijan

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Re: Vlock power connection question.

PostFri Mar 06, 2020 7:03 pm

To be 100% safe from ground loop damage you need to look for ISOLATED DC-DC Converters for each output. Regulated or not it makes no difference. It should be based on something like this https://www.tme.eu/en/details/thn15-121 ... -15-1212n/ or this https://www.digikey.com/product-detail/ ... D/10230157 As you can see true isolated modules are very expensive and limited in power (around 12V 1.5A max). So 2x or 4x isolated 12V 10A is something that impossible to provide in size of that D-TAP splitter box. Seems rencherindustries just attempt to sell you 10x overpriced box in 3D printed enclosure :shock:

Recently ARRI has released a technical paper entitled "Preventing Damage to SDI Outputs" viewtopic.php?f=2&t=107642

"This damage to the SDI connection can occur when connecting an unshielded power cable to an accessory that is already connected to the SDI output of the camera. If the plus pin is contacted before the negative pin, the BNC cable will close the current circuit resulting in the fatal damage of the included SDI driver chip which itself is not designed to handle such high currents. "

So solution is rather simple - never connect positive (+) DC power cable pin until you connect negative (-) pin.
It is not so easy to do in real life until you have dedicated switch on positive wire of DC cable, or specially designed DC connector which 100% always connects (-) pin before (+) pin.

Also first connect DC power cables, and only then connect monitor HDMI cable.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/

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