Steadicam Shadow, bypass dc/dc down converter in 24v mode.

[Jelle van der Does]

Hi all,

 

I own a Shadow sled and I'm mostly flying Alexas in 24v mode.

Instead of switching two 12v batteries in series I have had a 24v battery plate made to Chris' example. http://www.steadicamforum.com/index.php?showtopic=14350

It allows me to attach the 24v batteries that come with the camera on the bottom of my sled and supplies the 24v system.

 

A neat feature of the shadow sled is that it has a DC/DC step-down converter built in to convert the 24v to 14.4v (or something in that neighborhood) to supply the 12v system with power while simultaneously powering the camera with 24v.

 

This is where my problem comes in. I'd like to use one of my 12v batteries on battery plate nr.1 to supply all the 12v systems and the 24v battery on the bottom battery plate nr.3 to solely power the camera and nothing else since the Alexa is hungry enough.

 

What happens now is that as soon the 24v batt is attached it powers the DC/DC converter, even when I have my sled switched off. At some point when the voltage of my 12v batt drops low enough I assume the DC/DC system starts charging my 12v batt.

 

I figure the best solution to meet my wishes is to switch the DC/DC converter off so it doesn't help power the 12v systems and more importantly doesn't start charging my 12v battery.

 

Does anyone know if there is an elegant way to achieve this? I opened up the battery plate of the shadow sled to check out if it could be a simple solution but it looks quite complicated :-)

 

Your insights are much appreciated.

 

Cheers, Jelle.

Edited June 2, 2015 by Jelle van der Does

[Alan Rencher]

All you have to do is find where the DC converter is, and wire a switch to interrupt the 24V input on it. If you're not to keen on that kind of stuff, take the sled to someone who is familiar with system.

 

[Jelle van der Does]

Hi Alan,

 

thank you for the advice.

I make a lot of cables myself and fixed my modulus 3000 that had gone up in smoke (not because of my cables ;) ) a few weeks earlier.

So I guess I would like to take on the challenge.

 

Do you, or anyone else on the forum perhaps, already know where to find the DC converter?

 

Or is there someone who has done something similar?

 

Best regards,

Jelle.

[Rob Vuona SOC]

This is a perfect question for

Robert Orf

W-(818) 567-7915

C-(805) 404-3290

rorf@tiffen.com

USA

[Jelle van der Does]

Hi Rob,

 

Thanks for pointing me in the right direction!

 

Jelle

[Rob Vuona SOC]

Jelle,

This is the work around from Robert

-----------

Hi Rob..

 

Yes.. Jelle is correct in that the DC-DC converter will be powered up as soon as he connects his 24V battery, and yes the DC-DC converter would most likely start to charge the 12V battery if so connected. Best work around would be to pull out the circuit breaker for the 12V on the battery mount. Jumper the 12V battery on the rear battery mount to the sled via a D-TAP cable off of the battery and into the common LEMO connector (common ground) that he will use to plug the 24V battery into the sled. Doing so he will now get the 24V from the battery down below and 12V from the battery on the rear. I would also pull the 24V circuit breaker to play it safe.

 

Best regards

 

Robert Orf

Tiffen

818-567-7915

[Jelle van der Does]

Hi Rob

 

Thank you for making the inquiry for me.

You beat me to it :-)

 

I'm going to make something nice out of this.

Probably with circuit brakers in the bottom battery plate, on/off switches for 12v and 24v out of the side of the plate and a nice cable with lemo connector on the bottom plate end and Dtap on the rear battery plate end.

 

Pictures coming soon.

 

Rob, you have a shadow/phantom as well, is that correct?

What is your solution for flying hungry 24v cameras?

 

Cheers!