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#1 Jamie McIntyre

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Posted 21 October 2010 - 02:17 PM

Hi guys,

Is it possible to power the Alexa using the standard Arri 24v power cable? I've used the cable for the SR3 and the LT but I'm afraid to rely on my gut instinct and use it with the Alexa...

Thanks
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#2 Stefano Ben

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Posted 21 October 2010 - 03:02 PM

Hi Jamie!

Yeah!

From the Alexa User Manual:

The camera accepts any input voltage from 11-34 V DC. The camera
can be powered through the BAT connector or can be quipped with
battery adapters accepting V-Lock or Gold Mount batteries.

So the BAT connector it's the same fischer of the ARRI SR3 and 435! See pics attached!!!

Best, Steve

Attached Files


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#3 Benjamin Treplin

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Posted 21 October 2010 - 03:14 PM

Sure shouldn't be a problem. What kind of rig are you using?
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#4 Jamie McIntyre

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Posted 21 October 2010 - 04:00 PM

Using an Archer 2.

Cheers chaps!
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#5 Benjamin Treplin

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Posted 22 October 2010 - 03:12 AM

The Lemo 0B power connector looks a bit small (that's just me) it should handle the up to 100W the Alexa pulls.

Maybe Jerry could share some insights?
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#6 Jamie McIntyre

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Posted 22 October 2010 - 06:51 AM

That's a good point, I've flown the RED many times but that pulls just 75w right?

I'd be using two IDX powercubes on the rig too, in 24v 'mode'
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#7 Kris R Bird

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Posted 11 November 2010 - 02:48 PM

Yes, the Alexa's power port is standard!

That's a good point, I've flown the RED many times but that pulls just 75w right?


The RED runs at 12V, so it needs more ampres... 75W / 12V = 6.25A

The ARRI @ 100w would pull.... 100W / 24V = 4.17A

... which is childs play for the plugs, I can't remember the series # for the BAT fischer plug but it'll do 10A+ easily. HOWEVER! Your cables might not.

Kris
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#8 Eric Fletcher S.O.C.

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Posted 11 November 2010 - 02:59 PM

The Lemo 0B power connector looks a bit small (that's just me) it should handle the up to 100W the Alexa pulls.


a Lemo 0B is only rated for 2.5amps per contact
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#9 Eric Fletcher S.O.C.

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Posted 11 November 2010 - 03:00 PM

That's a good point, I've flown the RED many times but that pulls just 75w right?

I'd be using two IDX powercubes on the rig too, in 24v 'mode'



a Red pulls more like 9amps
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#10 Jerry Holway

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Posted 11 November 2010 - 05:46 PM

Jamie-

I just went on the Lemo website (lemousa.com), downloaded the catalog (again). Current ratings for the connectors are printed on page 45, with an explanation on page 178,

OB 303 connectors (the power connectors on the Archer2) are rated at 8 amps per connector. Good to go.

Jerry
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#11 Eric Fletcher S.O.C.

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Posted 11 November 2010 - 10:51 PM

I just went on the Lemo website (lemousa.com), downloaded the catalog (again). Current ratings for the connectors are printed on page 45, with an explanation on page 178,

OB 303 connectors (the power connectors on the Archer2) are rated at 8 amps per connector. Good to go.



EXCEPT that connector can only accept a 22 ga wire max and that can only handle 4.6amps so NO not good to go.

Doesn't matter what the connector and deal with if its wired undersized for the load.

If a 0B is sufficient Arri would have used it as a power connector...
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#12 Jamie McIntyre

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Posted 12 November 2010 - 08:33 AM

Seemed to work fine. :)
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#13 Jerry Holway

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Posted 12 November 2010 - 08:57 AM

Jamie,

Again, not to worry. Your test proves that.

But more on the specs.

I just revisited the specs. I mis-read the spec on the connector type. My bad. The info on the plugs is available online from Tiffen; check the the Archer2 manual, page 15.

The 0B 303 connector on the Archer2 is an EPG type for printed circuit boards. (see page 22 of the Lemo catalog).

It's downrated to 6 amps per contact from a normal 8 amps of the "straight" 0B plugs, which is what I said before. (see note 2 in the Lemo catalog, page 45).

The Archer2's power wiring is 14 gauge (and the power PC traces are at least that), so again, no worries with your 100W draw.

The Li-Ion batteries are nominally 14.8 volts each, nominally 29.6 volts to the camera, so the load at that voltage is more like 3.34 amps. At 26 volts (below the "knee" of Li-Ions, so no useful battery life at this point), the draw increases to 3.85 amps as the battery dies.

Jerry
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#14 RobinThwaites

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Posted 12 November 2010 - 10:00 AM

Hi Jamie

I have flown an Alexa with no problem on an Archer 2, if you want belt and braces I have also flown it with a PowerCube on the back of the camera with no issues.

Robin
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#15 Mark Schlicher

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Posted 30 August 2011 - 09:58 PM

Would like to revisit this question re: the Zephyr....

No published specs on the sled wiring, and the connectors are EGG.0B.303.

Can someone confirm the sled wiring gauge and capacity of the connectors?

Given the practicalities of a 0B mating connector, what is the maximum wire gauge for a cable and would that be sufficient for Alexa at 24V-100W, or for Red at 12V-75W?
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