Premium Members Jens Piotrowski SOC Posted July 2, 2012 Premium Members Report Share Posted July 2, 2012 I just wanted to post a little info I got from Greg Bubb a short while ago. He recommends feeding the Alexa 12V rather than 24V from the Ultimate sleds and he also makes the needed cable to do so. 2pin lemo to 2 pin fisher. Advantages are that you can turn off the sled and still have power to the camera and that you don't use the internal DC/DC converter (Ultimate 1), that saves energy and puts less stress on the system... I had great success with it running the standard Alexa/Camwave/MDR setup for almost 2 hrs of 3 a/b dionic/hc 90's. Cheers, Quote Link to comment Share on other sites More sharing options...
Premium Members Robert Starling SOC Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 I've run it both ways on my XCS Ultimate and have noticed virtually no difference at all. The only thing I've ever heard and I don't remember where is that the Alexa prefers 24 volts. The beauty of the XCS is that you have just about more power options than you could ever use. Robert Quote Link to comment Share on other sites More sharing options...
Premium Members Brian Freesh Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 The Alexa is a 24v camera. Feeding it 12v means it has to convert, so the manual suggests using 24v when there is an option. Sounds like Greg is suggesting to use 12v for the same reason on the XCS sled. Quote Link to comment Share on other sites More sharing options...
Premium Members Eric Fletcher S.O.C. Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 On my show I'm feeding my Alexa 24v from my Ultimate and have zero issues Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 I was going to try running it off of 12v and test run times vs 24. I bet there will be little, if any difference (meaning no problems) Quote Link to comment Share on other sites More sharing options...
Premium Members Jens Piotrowski SOC Posted July 3, 2012 Author Premium Members Report Share Posted July 3, 2012 we all agree, the ultimate has plenty of options. i was feeding it 24V before with zero issues, just wanted to share the info and i still think it's nice to turn the sled off, to save energy, without loosing camera power.... thanks guys, are you flying the ultimate now Ron? PS: yes,the Alexa uses 24V internally... Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 no ultimate -- pro2. I happened to be considering the same thing as you when I saw your post -- I am just playing with different battery configurations. Quote Link to comment Share on other sites More sharing options...
Premium Members James Davis Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 Out of interest, why do you guys power the alexa off of the sled? Are you talking about when using it with a codex or without? weight/convenience? I, haven't used it with a codex box yet, but I just tend to use the supplied 24v batteries, makes life easier and my archer handles it fine. Just curious. Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 It's all preference...but in my case I am always using the Boxx, which has to be used with a spacer when on the rear of the camera (to clear all the cables) so the camera becomes incredibly long with a battery added (plus the more ab plates...the more vibration). And, why not power from the sled -- one has all those batts down there anyways? I guess we could power all the aks from the camera then just add a bunch of steel weights? Quote Link to comment Share on other sites More sharing options...
Premium Members James Davis Posted July 3, 2012 Premium Members Report Share Posted July 3, 2012 Yeah I guess that makes sense, it is a pretty long camera, especially if you get a decent size lens on it. Quote Link to comment Share on other sites More sharing options...
Premium Members Jens Piotrowski SOC Posted August 29, 2012 Author Premium Members Report Share Posted August 29, 2012 FYI: when you feed the Alexa with 12V (14.4V) it will only output the same voltage on the RS (3 pin fischer) connector, rather than the normal 24V. this port is input V = output V, this according to Arri This is only important if you want to power 24V "only" accessories from that port. Quote Link to comment Share on other sites More sharing options...
Premium Members Benjamin Treplin Posted August 29, 2012 Premium Members Report Share Posted August 29, 2012 There is a lot of myth going around regarding Alexa power in/out. Copy/paste from the data sheets available on the ARRI website. Alexa Plus Data Sheet: Power In: Three inputs: BAT connector, battery adapter back and battery adapter top. All accept 10.5 to 34 V DC. 85 W power draw for camera and EVF-1 in typical use recording to SxS PRO cards, without accessories. Power Out: 12V connector: limited to 12 V, up to 2.2A. RS, EXT and ETHERNET: input below 24V is regulated up to 24V, above 24V: input = output voltage. Both RS and EXT connectors combined: up to 2.2A. ETHERNET: up to 1.2A. Maximum power draw is also limited by the power source. PDF Alexa Studio Data Sheet: Power In: Three inputs: BAT connector, battery adapter back and battery adapter top. All accept 10.5 to 34 V DC. When running over 30 fps with mirror shutter on, voltage of 18V or more is recommended. 90 W power draw for camera and OVF-1 in typical use recording 24 fps to SxS PRO cards, mirror shutter on, without accessories. Power Out: 12V connector: limited to 12 V, up to 2.2A. RS, EXT and ETHERNET: input below 24V is regulated up to 24V, above 24V: input = output voltage. Both RS and EXT connectors combined: up to 2.2A. ETHERNET: up to 1.2A. Maximum power draw is also limited by the power source. PDF Alexa M Data Sheet: Power In: Three inputs at the camera body: BAT connector, battery adapter back and battery adapter top. All accept 10.5 to 34 V DC. 85 W power draw for body in typical use recording to SxS PRO cards, without accessories. 40W power draw for head in typical use without accessories. A minimum of 15V power input to the body is required to power the camera head from the body through a standard SMPTE 311M hybrid fiber cable up to 50 meters, without accessories. The camera head has one 10.5 to 34 V DC power input that can be used to power the head independently from the camera body. Powewr Out: Several outputs at the camera body: 12 V connector: limited to 12 V, up to 2.2 A. RS, EXT and ETHERNET: input below 24 V is regulated up to 24 V, above 24 V: input = output voltage. Both RS and EXT connectors combined: up to 2.2 A. ETHERNET: up to 1.2 A. Maximum power draw is also limited by the power source. The camera head offers two RS connectors and one ETHERNET connector, with the same specifics as on the camera body. PDF In short: The Alexa is not a native 24V camera it is a native 10,5 to 34V camera. The RS output supplies always 24VDC or higher if the input voltage is above 24V. Hope this clears thing up. Quote Link to comment Share on other sites More sharing options...
Premium Members Erwin Landau Posted August 29, 2012 Premium Members Report Share Posted August 29, 2012 Currently on my second feature with the Alexa. I always fly with the battery attached to the Camera. Without, it felt to light... last year did an anamorphic show and before that 20 features in a row with the 535B... I guess anything will feel "light" after that. As my Dionic HC's are starting to show their age, I also don't feel like having my rig used as a permanently powered light meter, lighting tool or directors finder. Also on my first feature we used an HD transmitter that only could be powered by on-boards and on the current one we use my Canatrans as transmitter... maybe on the next one... Fly safe, Erwin Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted August 29, 2012 Premium Members Report Share Posted August 29, 2012 I also thought that power output was always the same no matter which battery powers it. I will try it today and report back. Quote Link to comment Share on other sites More sharing options...
Premium Members Jens Piotrowski SOC Posted August 29, 2012 Author Premium Members Report Share Posted August 29, 2012 I also thought that power output was always the same no matter which battery powers it. I will try it today and report back. the RS port will only provide 24V when 24V are being fed into the Camera, according to Arri Quote Link to comment Share on other sites More sharing options...
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