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Ac Power Supplies and Use

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George Griswold
Ac Power Supplies and Use
on Nov 10, 2008 at 12:01:17 pm

After a bad incident recently (I will make a separate post on all the gory details) I wanted to conduct a quick poll with two questions:

1. What power supply do you use with your HDX-900, Varicam or other full sized cameras that you work with? The HDX-900 is rated at 36 watts at 12 VDC, I don't know about the Varicam but wanted to find out what everyone is using with these power hungry cameras.

2. In what order do you connect to camera, power up Power Supply and Power Up Camera? Any other external power supply procedures that you follow?

Thank you,
George

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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Mark D'Agostino
Re: Ac Power Supplies and Use
on Nov 10, 2008 at 2:19:57 pm

George,
We own an HDX-900. We power it with Anton-Bauer Dionic90 batteries. They give incredible run time, have a power meter on the side and are relatively lightweight. They work so well we hardly ever use the ac power supply. When we do, we have an Anton-Bauer quad charger/ac power supply, (Interactive 2000). I've used that in helicopters when I've had very long flight runs and couldn't step out of the copter in mid-flight to change batteries. It works great. Just be sure the camera is off before plugging in and turning on the power supply
Mark

Mark D'Agostino
http://www.synergeticproductions.com


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Ernie Santella
Re: Ac Power Supplies and Use
on Nov 10, 2008 at 10:25:04 pm

I've been using Batteries 4 Broadcast batteries. Their charger also has a power tap for a/c power to our HDX900. Works perfectly. Nice to not have to carry a separate charger and power supply, especially on road trips. I started out with 2 Batts to test. I now have six 4010's (150WH)

http://www.batteries4broadcast.com/

Not to be a fan-boy for them, but I really like the batteries/chargers. Their customer service is unbelievable. Right up there with Portabrace!!

Ernie Santella
Santella Productions Inc.
http://www.santellaproductions.com


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George Griswold
Re: Ac Power Supplies and Use
on Nov 10, 2008 at 11:29:09 pm

Ernie,
I could not agree with you more-- the Batteries For Broadcast big batteries are fantastic. I have their batteries (8) but not a B4B AC supply. I just got a Sony brick type-- AC10 that is working out. In what sequence to you connect and power up?
George

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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Ernie Santella
Re: Ac Power Supplies and Use
on Nov 10, 2008 at 11:35:40 pm

George,

I plug everything in first, then power-up the charger, then turn on the camera. Been doing that for 2 years with no issues.

Question to you, what are you charging your B4B batts with if you don't have a B4B charger?

Ernie Santella
Santella Productions Inc.
http://www.santellaproductions.com


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George Griswold
Charger I use for B4B LI-ION
on Nov 10, 2008 at 11:59:18 pm

Ernie-

I have a great Sony 4 position Li-ION charger I got at a Lockheed Martin auction with a D35 (long gone). Great charger...

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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cowcowcowcowcow
George Griswold
Re: Ac Power Supplies The Death of my HDX-900
on Nov 10, 2008 at 11:50:56 pm

Death of an HDX-900: Bad Power Kills

By George T. Griswold, Video Now; New Orleans

The last week of October I had two bookings so I sent a crew to get some behind the scenes coverage on a movie that was shooting in just outside of New Orleans. The experienced crew took my HDX-900 that I had owned for over 16 months, a Panasonic LH-1700 monitor and off they went.
On the set they were on battery power when they were shooting some B-roll and then positioned to get some interviews. As is normal on motion pictures sets the availability of the actors is spotty and involves long wait times. They decided to switch to external DC power to set up the lighting and standby for the interviews. My power supply that I have used for the last 16 months is a medical switching power supply (15 VDC 5 A) that I got from Digikey and has worked flawlessly in that time. I have used it with this camera and a SDX-900 in all conditions with many different monitors in humidity and kitchens with wet floors—conditions that would likely reveal a ground fault if one existed. The camera was switched off (so I am told) and the power supply plugged into the 4 pin EXT DC jack. The power cords from the camera power supply and a 17” (LH-1700) Panasonic monitor were both plugged into a cube tap. The crew then plugged the cube tap into an AC distribution box supplied by the electrical department. When they plugged the cube tap into the box, they saw a visible arc. The camera would not power up and the camera breaker was tripped and would trip when any power was applied by battery, but not EXT DC. The monitor was up and running fine. By phone I had the crew find someone from the Electrical Department to check the circuit—it tested OK. The monitor was OK too, works even now just fine--- obviously I would have preferred the damage was the other way around. The damage was confined to the camera.
Let me say at this point that this is not how I power up a setup like this--- ever. What I have always done is power up the supply first then connect it with the camera off. In this sequence the power supply has stabilized at its working voltage and is ready to go--- to a certain extent looks like a battery when plugged in. This is not a good idea for some supplies that go way over the listed voltage rating until they see at least some load. More about this later on….
When I buy a piece of gear I always spring for a full service manual—at the very least there are a few good tidbits to learn and in the case of a problem I have been able to make repairs without sending the gear out. When I got the camera back that evening after completing my own shoot (difficult to concentrate on that knowing that my HDX was down for the count) I found the schematic page for the board where the DC comes in, a roughly 3” X 3” one with the circuit breaker that is inside on the bottom behind the shoulder pad. I opened the panel to reveal the Rear Audio Board. The damage here was worrisome at best. There is a small soldered in fuse that catches the DC IN from the XLR that had blown, but power from the battery voltage was still getting to the breaker and “popping” it right away. There are two solid state “switches” in parallel that are driven by a logic signal from the front power switch that turn on the camera and the top of one was blown off. This DC input board that feeds the rest of the camera DC circuits was seeing a dead short. There was the smell of death in the air: burned plastic. There is a DC regulator board, but when you replace it there needs to be a firmware update/ check so with an insurance claim a definite possibility I walked away from further troubleshooting. Time to send off the HDX-900 to an experienced and trusted shop.
I considered sending it to Panasonic, but decided to send it to Roger Macie so I could follow the progress of the diagnoses and be able to discuss my options with the tech working on the camera. In the past I had Roger setup an Ikegami HL-57 and it still makes a wonderful picture. After a few days I spoke with a trusted tech at Macie that I had spoken with many times before and he said, “it is time to call your insurance company”. Long story short: the camera suffered a massive surge event and was beyond repair. In addition to the blown devices I saw, every card had physical damage to capacitors. The optical CCD assembly tested dead, the viewfinder was not working—the repair would entail massive board and component replacement and could not be guaranteed after all that. This confirmed what I had suspected from what I observed—the camera was trashed.
Thankfully all my gear is insured with an all hazard, replacement cost policy and am being paid 100% on my damage claim and received my new camera last week. But I wanted to explore the cause of this calamity hoping to share it with others and not repeat it myself.

Power Supply: I would never have plugged in both devices at the same time regardless if I thought they were turned off or on. (That being said, I am sure in the heat of battle cameras and monitors are powered up in all the different combinations imaginable--- as far as I know there is no common “right way” of doing this) Having two switching supplies coming up at the same time is asking for trouble—AC line voltage sag or possible interaction of the supplies. Also, as the DC Voltage Out rises that is still entering the device with unknown consequences. There is a branch circuit that feeds the camera logic and a transient on power up may have switched the camera to ON (or it was actually in the ON position) as voltage was rising. This is when the camera draws the most current (inrush surge: caps charging, devices drawing current to operating levels). With V IN low, even for less than a fraction of a second, the current drain would go very high during this period. From what I can tell this is what killed the camera. The power supply tested OK after the incident, but I buried it in my backyard just to be sure never to use it again. The operating voltage range for the camera is 11-17 VDC so I have settled on a Sony V-mount brick supply that is 16.7—a little close to the bone, but a high quality supply. When the Sony is powered up on the camera the viewfinder voltage readout says 15.9 VDC. I looked at the IDX supplies, but did not really think that much of them.

HDX-900DC IN Fault Protection: I was hoping to see an advanced protection scheme where the DC comes into this camera, but was underwhelmed. Not to blame the victim, but I would say that you should not take a lot of comfort in what protection is offered here.

There is a brute force 6A breaker, a fuse and two NTC (negative temperature coefficient) thermistors that appear to be for inrush current protection. The thermistors protect only the ECU (CF201) and the external DC Hirose jack (CF202). The main incoming unregulated DC inside the camera is always "protected" by the breaker (CB201) for battery and EXT DC and additionally a fuse (F201) when powered by the external DC jack. When powered with a battery the breaker (CB201) alone protects DC. All the devices are thermal / current actuated and have a time delay before they kick in. Whatever the cause for the degraded DC IN these safeguards failed to save the $27,000 camera.
See schematic in attached JPEG with components marked.

Takeaway:

-Use batteries all the time for the ultimate in safety. Not always practical.
-When using a power supply, have it powered up right from the start so if you or a helpful assistant plugs it into your camera it is up and running.
-Power up one device at a time.
-Double check integrity of the location grounds.
-Have Camera PS and Monitor on the same outlet, branch circuit or surge protector. Not essential, but puts both of these interconnected devices on the same power phase and on the same ground.
-Use a high Quality Surge Protector like the ISOBAR ULTRA. In 27 years in television I have never used nor have I seen anyone use a surge protector when powering gear in the field, but why not? Tripp-Lite makes a small Isomax Ultra two outlet unit that you can get for $50 on Ebay. I got two.

I hope this helps somebody out there in the future. Be careful out there!
George Griswold





George Griswold
http://www.videonow.info
New Orleans, Louisiana


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George Griswold
HDX-900 Power Input Schematic JPG to view
on Nov 10, 2008 at 11:57:41 pm

Rear Audio Board that handles incoming DC from battery and external DC.

I would do a save as, and then view it since it is dimensionally large at 8.5X11.

Cheers,
George


hdxschematicwithnotes400k.jpg



George Griswold
http://www.videonow.info
New Orleans, Louisiana


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Robin Probyn
Re: HDX-900 Power Input Schematic JPG to view
on Nov 11, 2008 at 8:41:59 am

So you should always power up the mains adaptor before powering up the camera?

Thanks



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Ernie Santella
Re: Ac Power Supplies The Death of my HDX-900
on Nov 11, 2008 at 12:07:37 am

George,

After reading your post (Horrible story) I just found a Tripp-Lite 2 banger on ebay too! Can't be too cautious. Thanks for the heads-up!

Ernie Santella
Santella Productions Inc.
http://www.santellaproductions.com


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Bruce Alan Greene
Re: Ac Power Supplies The Death of my HDX-900
on Nov 11, 2008 at 7:43:23 am

George,

Sorry to hear about your loss.

I have one question for you: Where do you get your insurance? I got my policy renewal recently and the new policy seems to not really cover me if I rent out the equipment. Certainly not if someone renting it steals it. Not so good.

About power supplies: I use an anton bauer titan charger/power supply that replaces the battery on the back of the camera. I must be careful with it as it will not power the camera, on board monitor and down converter at the same time without blowing and needing repair.

And a little story:

A few years ago I was operating on a tv movie with two Sony/Panavision f-900 cameras. On the first day my assistant insisted on using AC power to avoid changing batteries.

Sitting on the dolly I noticed the feel of ac current coming through the camera body. No one believed me--until there was smoke coming out of both of the cameras. Luckily, only the SDI adapters were fried.

The cause: Improper wiring from the electric department or faulty wired cable placed 220v into the edison ac outlets and no ground.

The lesson: Never plug sensitive electronic equipment into the company/generator power system without 1st checking the power. I once lost a Sony CRT monitor to faulty movie power and have learned my lesson albeit at less cost than a camera. I had to run the monitor on battery power for the rest of the movie, so I was lucky.

Good luck with your claim, and please let me know about the insurance company.




Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


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Charles Caillouet
Re: Ac Power Supplies The Death of my HDX-900
on Nov 28, 2008 at 1:22:36 am

George,
Thanks for that complete report.
Here is a related event that i can offer...

I was on a job a few weeks ago and we were using four Tripp-Lite power strips, two of which were plugged into a third one and the fourth one straight into another outlet. Both strings were apparently on the same circuit. After checking out the temporary installation, we went home for the day, but a couple of hours later we got a call from someone in the office near the installation that she smelled something burning, saw some smoke coming from one of the strips and unplugged the whole thing. Post mortem showed that filter caps in all four strips were blown out; the strips were still working, but presumably the surge protection function was gone. Nothing else in the office was damaged, even a printer and phone plugged into one of the strips.

I suspect that the failure of these surge protectors was related to some interaction among the components but it is still not clear to me what really went on. We did not have power monitoring so we don't know if there was a surge but all indications are that there was not. We were on shore power and apparently nothing changed. There were no known thunder storms in the area.

This brings up a couple of issues:

First, the safety office at the large facility where this event occurred recommended that power strips not be cascaded, even if the total load is well under the breaker ratings in the strips. They were a bit vague about the reasoning but were adamant that it was against their policies. After some discussion, we found that they had experienced a similar unsolved event some time prior to ours, so they didn't give us a hard time; they just recommended that we don't do that. Kind of "If it hurts when you laugh, don't laugh." advice.

Second, in the past, i have found that surge protectors often are the source of ground current leakage, which is a big pain in analog video systems. It is second only to neutral/ground reversals in causing ground loops and audio hum. So i would leave your surge protectors at home and get some good quad boxes with no electronics in them; you can cascade those till the breaker blows. Of course, don't overload the circuits and don't use underrated wire or receptacles when you draw heavy loads.

Anyone else have experience on this subject?

cheers,
C. R. Caillouet



C. R. Caillouet
Vision Unlimited/LA
HD Production Technical Support since 1987
...searching for the right tool for the job...


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George Griswold
Re: Ac Power Supplies The Death of my HDX-900
on Nov 28, 2008 at 3:08:40 am

Charles,

Thanks for those observations-- You are right never to cascade the surge devices-- adds no benefit, causes odd behaviors and in fact invalidates the warranty/ guarantee that come with them. As far as not using them-- that remains to be seen in my case; my application is Camera and a monitor with no other ties to a ground other than earth (wireless mics,no switcher or remote devices). I have never used nor recommended using a QUALITY surge device in 27 years, but have not had problems when used in a simple EFP setup over the last 40 days. The Ground leg feeds right through the box as I recall (popped one Iso open of just to see) so chassis downstream are brought to that potential.

At this point I think it better to use one unless it creates a problem. As it stands I will be lucky if they don't cancel my insurance after my whopper claim-- not to mention the cardiac stress, tears and gnashing of teeth. In the end a surge event did not kill the camera, but it has created a culture of extra caution in me and my freelancers.

Hope to see you soon...
George

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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