Voltage to look at not to fry accesories/power ports in the camera

[davide sorasio]

Hi everybody! One of my biggest fears on set is to fry camera accessories because of misunderstanding of voltage etc etc. I know that some accessories like TV logic need 12 volts while other like follow focus motors etc need 24 volts. What I do not understand is how do I know which voltahe is the correct for each accessories and what's the voltage of each power port (If I'm not wrong RS ports are 24v while Dtap is 12-18). Is there any rule of thumbs or does anybody have a more defines explanations that goes beyond my knowledge of the topic? My understanding of electricity is pretty basic too.

Thank you in advance for the help!

[Evan Walsh]

If unsure always ask a technician at the rental house. You can also consult a product's website/operation manual to find the acceptable input voltage range.

Teradek's for example can accept between 7-28 volts, you could safely power it off a 12V 2-pin lemo/ptap cable or a 24V power out on a Panaflex.

Not always, but sometimes you can find a label with the acceptable voltage range near the power input of a device.

 

If I understand this correctly, RS ports (3 pin Fischer), will pass through what ever power is being fed to the camera, either 12V or 24V, where as the 2-pin Lemo's will be regulated to 12V (in the case of the Alexa at least).

 

One thing to consider if afraid of frying accessories is polarity. Many accessories will use the 2-pin Lemo connector for power, but different brands can use different polarities. If you used a Bartech's 2-pin Lemo cable for power on a Teradek you could damage it.
I took this from Media Blackout's 2-pin Lemo page, "Pin-1 positive voltage, (Bartech, Letus, Redrock, etc.), and Pin-1 ground (GND) (Teradek, Preston, Paralinx, Arri, etc.)".

 

Just be sure to not mix up cables between the accessories when shooting.

Edited May 6, 2016 by evanwalsh