Epic power shutdown on power up of accessories

[Bruce Forrest Byker James]

I'm running an Epic, Bartech Follow Focus Receiver, Heden focus motor, (both from the stage) and monitor off a rather old Video SK and when I turn on either the follow focus or the monitor, the Epic shuts down. I can just always turn accessories on before the camera, but I'm wondering if anyone else has run into this and if they've come up with any kind of solution. Could this be some kind of power surge or drop the Epic doesn't like? Is some kind of power conditioning to the Epic the answer?

 

Thanks,

 

- Bruce

[Kyle Wullschleger]

I've had this experience as well when turning on an analog bartech that's powered from the same source as the camera which has led me to assume that it is indeed a power surge. It doesn't happen with fully charged batteries, so it seems when the voltage is already lower that the power it takes to turn the bartech on pulls it below the Epic's range.

 

My solution has been to power the bartech through the sled - or like you said, power it on before turning the camera on.

[Afton Grant]

The solution is multiple batteries to spread out the working load. A single battery can only provide a certain amount of power. Put too much demand on it and one or more of your devices will fail.

[Victor Lazaro]

I've had this issue multiple times on my Zephyr with a single AB battery. Now I fly with a separate battery on the back of the camera. Anyway, it adds weight to the rig and pushed the CG a little fit back which is good with the Epic or your film plan ends up behind the centerpost with some configurations.

battery in the back and your Red is happy.

[Bruce Forrest Byker James]

Thanks for the responses. It occurred to me that I could also just leave a REDvolt battery in the side handle of the camera, though I'm not sure how the Epic integrates that battery if the other power supply is just power - no data.

 

So batteries seem to be the simple (and best) solution, but just out of curiosity, has anyone tried some kind of power conditioning device (if such a thing exists)? With my really limited electronics knowledge I thought that perhaps a circuit with a capacitor in it could stabilize the power supply.

[Afton Grant]

The Ultimate sled is probably the most sophisticated rig you can buy to squeeze every drop of performance out of a battery, but even that can't do magic. A single battery can supply a finite amount of power. Surpass that amount, and things don't work. It's that simple.

[Alan Rencher]

A revolt may act like a UPC, but Red's can be flaky, and they don't always switch to another power source when the voltage drops.

 

Also, what kind of batteries are you running? A Dionic HC or other high load battery should be able to run those of the wiring on your sled can handle the load.

 

Edited June 6, 2013 by Alan Rencher

[Victor Lazaro]

Good to see no one jumped on this thread with the wire gauge. Haha

I wouldn't rely on the side handle. It's been finicky and doesn't switch power sources properly and it always looks bad when the error message shows up in front of the owner of the camera because you tried something new. Hot brick on the back of the camera. Another at the bottom of your sled and you are good to go. As for a device that will regulate the power. It's probably going to be more expensive than a simple battery. And you don't need to swap as often with two batteries.

[Bruce Forrest Byker James]

This is at an educational institution and is our oldest Steadicam (Video SK). The setup we have is an IDX adapter box that houses two Frezzi NP-1 batteries. I think it's around 80Wh total.

 

There's no problem with offending the camera owner, because that's us, but I'd rather avoid improper shutdowns. The problem is that it's hard to get the 20 or so students who may use this setup to always power the accessories first, then power the camera. On the upside, the work I've been doing on this setup is likely a stopgap measure until we get a Zephyr later this summer.

 

Sorry to bring something up that sounds like maybe it's the third rail of this forum (I'm new here), but does anyone know what the wire gauge is in the post of a Video SK? It hasn't started heating up or smoking yet. :unsure:

[Tom Wills]

Ah, Temple's old rig! God knows my Bartech's been on that rig a few times! Glad to hear you're getting a Zephyr, should be a big upgrade for the students.

 

NP1s aren't exactly high capacity batteries, and likely with their age they're not going to have the kind of capacity to start everything at once, especially with the Epic being rather power-hungry (which is deceptive, because of how small the body is!). Likely rather than any protection kicking in (like sometimes happens with Dionics and other lithium-ion "smart" batteries), you're just getting a significant enough voltage drop with the startup current of the accessories that the Epic is shutting itself down, because it's no longer receiving enough voltage. The wire gauge may play into this as well - the SK doesn't have very thick wiring, not sure of the actual gauge, but it passes through a tiny little Hirose connector from the base, so it can't be much. That could certainly add to the voltage drop too.

 

As others have said, running an onboard battery on the EPIC makes all the sense in the world in this scenario - the setups your students are flying are generally with primes and a small mattebox, which even with a battery plate and one of your old RED bricks should still be under the 19 pounds your SK is built for. I'm a big proponent of flying the Epic with a battery on the back anyways - I think the camera is just too light to fly well without it.

[Victor Lazaro]

agreed, also I want to add that I do get the shutdown on my Zephyr and brand new Anton Bauer, so upgrading the rig will give you a better sweet spot for the red and it's weight, but will not solve the issue of the shut down. Also, if you notify the students do be careful with the bartech, it could become a habit to turn on the camera last, and you have a way to see if the students remembered the procedure (that big red box on the screen on the next power up).

Anyway, turning on the camera after checking all the aks you put on it is a good thing, avoid power differential when you plug a video tap (read that on another thread). also saves some battery on the camera.

[Bruce Forrest Byker James]

Thanks everyone for the helpful suggestions and quick responses!