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Zephyr Power Configuration


Lee Clements

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I'm looking at a Zephyr for purchase sometime in the near future, and I'm trying to suss out what I want to start out with for accessories.

 

My questions are about the 12v/24v options.

 

1. Is this a future-upgradeable option, or would the sled come pre-wired with it?

2. If I were using a 24v camera but 12v accessories, what would I need to switch the 24v back to 12v for the accessories (or would that even be possible)?

3. Are there 24v batteries, or will it always require two 12v batteries? I imagine any 24v camera will be beastly enough to require two batteries to counterbalance anyway, but just in case...

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1. Yes, you can upgrade in the future, the sled is wired in such a way that the 12/24V plate simply plugs into your existing wiring. The adapter has a simple toggle switch to go from 12-24V operation.

 

2. All the power connectors are wired together on the Zephyr, so when in 12V mode, 12V only is available on all connectors. IN 24V mode, all connectors have 12V OR 24V available, depending on the pinout of your cables. With this implementation, when you are in 24V mode, the 12V accessories are still getting 12V, due to the way the 3pin lemos are wired. You do need correctly-wired 12V and 24V cables, obviously. Tiffen cables are wired to the appropriate standard. Peter or Michael from Tiffen can fill you in on the details.

 

3. The Zephyr 12/24V adapter is designed so that you always use two 12V batteries to create 24V (or switch the adapter to 12V so both batteries work in tandem for extended runtime with 12V cameras.) There are several threads on "power-hungry cameras" but I will give you the bottom line: camera configurations that are in excess of 90-120W, such as Alexa, will be at (or arguably above) the recommended current draw of the Zephyr sled, and definitely above the recommended current of many batteries in common use. The advantage of 24V with Alexa is that higher voltage=lower amps, which stresses both your sled and batteries less. Read the threads and operate at your own risk. That said, you should probably be using no less than two Dionic HCx or IDX Powercubes (something rated in excess of 100-120 watts) for a power-hungry camera. Anything less and you will be cooking your (or the rental houses') battery. If you are using a 24v film camera, your power draw is much less, so you are mostly concerned about mass and distribution of mass. The adapter definitely helps with this.

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Fascinating. The only 24v camera at my school is an Arri SR3, which I've just flown on their Glidecam, so I know it'll work with the Zephyr, but obviously the Glidecam doesn't do power through the sled (one of its oh-so-many shortcomings.) I'll be sure to check the other thread about power-hungry cameras, but the market around VA Beach isn't exactly saturated with much above a RED One.

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Red one can stress batteries even more thank Alexa, being a 12V camera that draws something like 70 watts, if memory serves. So dual batteries are a must in my opinion.

 

I also run dual (dionic 90) batteries with heavier broadcast cameras simply to enable me to keep the post short and the masses better distributed.

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So the options for 12 and 24 volts is so that when one battery dies the second one can start working and swap out the dead one with a fully charged battery? I was curious as well about the 12/24 options that the rig has. Also Lee How much does the ARRI SR3 weigh with the set up you had on the glidecam?

Edited by Matthew L. Perez
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Matthew,

 

The hot-swap is only in 12V configuration. No hot-swap in 24V

 

The other main benefits of the battery hanger are:

- better weight distribution and ability to mount sufficient weight to balance heavier cameras (the main benefit, IMO)

- mix 12V and 24V AKS

- extended runtime for power-hungry cameras

- run in 24V mode for a 12/24V camera, to reduce current draw at a given power demand (100w at 24V = half the amps as 100W at 12V. This minimizes the possibility of problems due to heat buildup in the Zephyr's 22AWG sled wiring)

- separate 12V power sources to split the load if desired*

 

* a word of explanation: to do this you unplug the regular battery paddle from the sled and power AKS such as the monitor other AKS mounted to the bottom spar with the D-tap on that paddle. Keep the aux battery hanger plugged into the sled to power items on the topstage. Tiffen has chosen to deactivate the d-tap on the aux battery hanger for some technical reason, so if you unplug the aux hanger you won't have access to that battery's output unless you had a lemo adapter made.

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Matthew,

 

The hot-swap is only in 12V configuration. No hot-swap in 24V

 

The other main benefits of the battery hanger are:

- better weight distribution and ability to mount sufficient weight to balance heavier cameras (the main benefit, IMO)

- mix 12V and 24V AKS

- extended runtime for power-hungry cameras

- run in 24V mode for a 12/24V camera, to reduce current draw at a given power demand (100w at 24V = half the amps as 100W at 12V. This minimizes the possibility of problems due to heat buildup in the Zephyr's 22AWG sled wiring)

- separate 12V power sources to split the load if desired*

 

* a word of explanation: to do this you unplug the regular battery paddle from the sled and power AKS such as the monitor other AKS mounted to the bottom spar with the D-tap on that paddle. Keep the aux battery hanger plugged into the sled to power items on the topstage. Tiffen has chosen to deactivate the d-tap on the aux battery hanger for some technical reason, so if you unplug the aux hanger you won't have access to that battery's output unless you had a lemo adapter made.

 

This got me more confused. what is the issue and what are you trying to achieve?

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I was trying to answer Matthew's question about hot-swap and other advantages of the plate. Primarily clarifying that the hot-swap capability is only available in 12V mode.

 

For me personally, the aux battery plate is mostly useful for flying heavier video cameras by adding a second battery as counterweight. It also helps distribute the weight so that dynamic balance is easier. Increased battery life is a bonus.

 

The other benefits are minor by comparison, depending on specific configurations and needs. Power-hungry 12V cameras like Epic benefit from extended runtime provided by two batteries...but also are light enough that usually you are better off with a battery mounted to the back of the camera. If you are trying to fly Alexa on Zephyr, you need battery weight below, and since the camera's already so heavy for Zephyr you'd want to avoid adding a battery on the camera. The challenge is that the Zephyr's wiring is marginal for the Alexa power draw, resulting in voltage drop and heating. The problem is mitigated somewhat by running the sled at 24V (with a 24V Alexa power cable). Higher voltage means lower amperage, so lower heat buildup.

 

The separating of the two batteries is a kind of theoretical benefit. I've never used it that way, but perhaps it would be useful. It adds the ability to power everything on the top stage separately from the bottom of the sled.

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The challenge is that the Zephyr's wiring is marginal for the Alexa power draw, resulting in voltage drop and heating.

 

No the Zephrys wiring is totally inadequate for an Alexa or even an epic

 

 

The problem is mitigated somewhat by running the sled at 24V (with a 24V Alexa power cable). Higher voltage means lower amperage, so lower heat buildup.

 

Doesn't work that way. The Watts are the same, and thus the losses are the same

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DC 12v and 24v volts can run in series and parallel. With two batteries, in parallel, you are running 12v.

With 2 batteries in series, you are running 24v.

Lets say a AB battery is good for 100 amp hours.

With two of them in parallel you get 12v, 200 amp hours.

With two of them in series, you get 24v 100 amp hours.

 

Forgot to add... Eric is correct. Pulling 8 watts at 24v is the same as pulling 8w at 12v.

You are pulling 8w either way.

The only difference is you have less aH at 24v compared to 12v if you are

running off 2 12v batteries.

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Watts is watts. Correct.

 

Never said that 12V vs. 24V made a difference in runtime. Only makes a difference in lowering the amperage being pushed through the 22AWG wiring of the Zephyr sled. This, in my understanding, reduces the heat buildup in the wires.

 

Talking about heat buildup. Given the same power draw (watts), Greater voltage= lower amps=less heat buildup.

 

 

As for "marginal" vs. "totally inadequate"...these are subjective descriptions and subject to a lot of factors that have been discussed before.

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