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Powering both BMP4K and BM Video Assist with D-Tap battery
Posted:
Fri Nov 19, 2021 3:33 pmby cambiz
I have a BMPCC4K powered by a V-Mount battery w/ D-tap cable. I have read that one shouldn’t power the monitor the same way. My monitor is the BM Video Assist and I was wondering if I could power it by way of a Zacuto dummy battery: LP-E6 to D-tap Cable. Since the battery is the same as the canon batteries used to power the Video Assist? Also there is this option: SmallRig Power Cable for Blackmagic Cinema Camera/ Blackmagic Video Assist/ Shogun Monitor 1819.
Please let me know if these options are safe and if not, are there other options available?
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Fri Nov 19, 2021 4:06 pmby Mark Foster
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Fri Nov 19, 2021 10:27 pmby cambiz
cambiz wrote:I have a BMPCC4K powered by a V-Mount battery w/ D-tap cable. I have read that one shouldn’t power the monitor the same way. My monitor is the BM Video Assist and I was wondering if I could power it by way of a Zacuto dummy battery: LP-E6 to D-tap Cable. Since the battery is the same as the canon batteries used to power the Video Assist? Also there is this option: SmallRig Power Cable for Blackmagic Cinema Camera/ Blackmagic Video Assist/ Shogun Monitor 1819.
Please let me know if these options are safe and if not, are there other options available?
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sat Nov 20, 2021 1:52 amby Patrick Spectra
I use two of these, one for my pocket 4K and one for Video Assist 4K on my Ursa Mini Pro 12
https://www.antonbauer.com/en/antonbaue ... -27/p-1934Sent from my iPhone using Tapatalk
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 2:31 amby Dmytro Shijan
Powering camera and monitor connected to camera HDMI port from the same battery always cause the "Ground Loop" problem and in some situations may permanently damage camera HDMI/SDI port. To avoid HDMI/SDI port damages It is recommended to follow safety guide provided by ARRI
https://www.arri.com/en/learn-help/lear ... ion-196368"Cameras and accessories with SDI/HDMI connections can be damaged when connecting power cables. If the BNC/HDMI cable is already connected and an unshielded power cable is plugged in, the plus pin can briefly make contact before the minus pin. The electrical circuit will then be closed through the BNC/HDMI. This can fry the SDI/HDMI board in the camera or accessory, even when they are powered down. To avoid this, follow our two safe cable connecting rules:
When connecting cables: FIRST connect power cables, THEN the BNC/HDMI.
When disconnecting: FIRST disconnect the BNC/HDMI, THEN power."
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 2:46 amby Harold Tomlinson
If I understand this correctly, this is only an issue if the battery is connected and providing power while the HDMI or SDI are connected or disconnected. Is it a problem (or could it be) if all the connections are made or broken when the battery is not connected? That is, can it be an issue during operations or due to power devices on or off as opposed to when connecting or disconnecting?
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 10:02 amby Mark Foster
the problem arises when connecting and disconnecting in the wrong order.
therefore, I had posted the necessary information above.
this applies to both SDI and HDMI connections.
.
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 1:46 pmby Harold Tomlinson
I just want to confirm that this is strictly a hot-plugging issue and that if the battery is not connected when the cables are connected it is not a problem to power the camera and monitor from the v-mount.
The sequence specified does not include the battery, just the cables. If the battery is mounted on a v-mount or some other holder, I assume it should be connected last and disconnected first and that the cable order does not matter. Would that be correct?
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 2:37 pmby Dmytro Shijan
If the battery is not connected when the cables are connected it is not a problem to power the camera and monitor from the v-mount.
Not sure if i understand your point. Did you mean in-camera battery used in pair with V-Mount external battery?
It is not a hot-plugging issue. It is issue due DC power plus connected before minus (ground). In this scenario power splash somehow goes to HDMI cable and depending of luck burns or sometimes don't burns HDMI port in camera or in monitor.
HDMI and other USB-like plugs designed in the strict specification and "minus (ground)" always touched first.
But DC barrel and D-Tap and other DC connectors are designed in very random ways and it is unknown if "plus" connected before "minus (ground)", or if "minus (ground)" connected before "plus".
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 2:53 pmby Harold Tomlinson
I don't have the battery in my camera or on my monitor but I connect both to a d-tap strip which is connected to a v-mount plate. I attach the battery after the cables are connected.
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sun Nov 21, 2021 3:05 pmby Dmytro Shijan
I don't have any info about V-Mount pins connection order specification. But if V-Mount battery touches "plus" pin before "minus (ground)" pin when you attach V-Mount battery to V-Mount socket, and if HDMI cable was already connected to monitor - this is ground loop situation and this may permanently burn HDMI port.
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Wed Nov 24, 2021 5:03 pmby cambiz
Since the damage might be extensive let me play dumb and repeat what's been suggested:
Dmitry Shijan :"When connecting cables: FIRST connect power cables, THEN the BNC/HDMI.
When disconnecting: FIRST disconnect the BNC/HDMI, THEN power."
IF that's the answer to my post please let me know and thanks.
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Thu Nov 25, 2021 7:41 pmby Phil999
the easy to remember routine is, always disconnect the video cable from the camera before changing anything with power supply.
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sat Jul 30, 2022 4:34 pmby cambiz
HI,
Would powering the monitor separately with a Core SWX PowerBase Edge Lite 49Wh 14.8V Small Form Cine Base Lithium-Ion Battery Pack, for example deal with the problem of powering everything with one main battery?
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Sat Jul 30, 2022 6:01 pmby Howard Roll
cambiz wrote:HI,
Would powering the monitor separately with a Core SWX PowerBase Edge Lite 49Wh 14.8V Small Form Cine Base Lithium-Ion Battery Pack, for example deal with the problem of powering everything with one main battery?
47Wh isn't much output for the expense. Consider that Anton Bauer NPs are also 47Wh at 1/3 the size and don't require cables or rigging compromises. The downside is the weight distribution. I power camera and monitor from the same V-lock for ergonomics and efficiency not gear safety.
The key to electronic safety is better grounding between all devices so that the shield of the SDI or HDMI doesn't provide the path of least resistance.
Good Luck
Re: Powering both BMP4K and BM Video Assist with D-Tap batte
Posted:
Mon Aug 01, 2022 11:37 pmby cambiz
Hi Howard,
Thanks for your reply. I am just leery of powering both the camera and the video assist monitor due to possible HDMI grounding issue. I have various adapters that are shielded and also have heard about the sequence of turning on the camera than powering the monitor. But afraid just in case...
Thanks,
Cambiz