View Full Version : Uninterruptible 12vdc Camera Power Supply?
Matt Uhry
05-16-2007, 11:43 AM
It seems that with the Red it would be useful to have a AC power unit that incorporated a UPS in it -
Maybe it could give you 20 mins of camera run time while you move setups and find the next power outlet and then charge itself when the AC power is restored.
It's going to be important to protect those drives from power disconnect when writing data.
Some kind of visual alarm to let you know that you are living on borrowed juice. Flashing LED's that go faster when the party is almost over?
I know you could tape together a computer UPS and a Red Charger but that would not be a very small or light unit.... I'm hoping for something trick that is not too large or heavy.
Just an idea -
Matt Uhry
www.mattuhry.com
Craig Schober
05-16-2007, 12:10 PM
It seems that with the Red it would be useful to have a AC power unit that incorporated a UPS in it -
Maybe it could give you 20 mins of camera run time while you move setups and find the next power outlet and then charge itself when the AC power is restored.
i think the additional size and weight of any ups on a red charger wouldn't be worth it. the most expensive laptops don't have any ups and they're constanly moving data. i think the battery level meter available in the evf/lcd monitor should be enough. and if you have people pulling power or you're tripping breakers, you have other problems that a ups won't fix.
what would make a difference to me is if you have the battery on the charger while it powers the camera...if power does go, does the power immediately go to the battery so that there is no interruption?
JohnF
05-16-2007, 02:04 PM
Simple solution #1:
Two power connectors, one for the battery packs the other for a mains power supply (AC/DC to 12V).
One takes over from the other whenever they're disconnected or power cuts out . Plus have a "safe shutdown" function that makes sure that the camera can shutdown whilst safely writing remaining data to avoid corruption and/or any other kind of disk damage.
There will always be situations where one will squeeze every second of juice from the power supply and, in my experience, often when the shot occurs!
JohnF
Matt Uhry
05-16-2007, 03:38 PM
Hi Wigby,
I was not referring to the charger, but rather to an AC power supply. The camera has only one power input, a 2-pin Lemo, so it's an either battery or mains kind of thing. In some more docile situations it will make more sense to use mains power instead of battery.
the most expensive laptops don't have any ups and they're constanly moving data.
That's actually my point, a laptop reverts to battery when you unplug it. The camera is doing laptop like functions computing and writing data to a drive or flash. If the write is suddenly interrupted by a kick out it's not a good thing?
Matt Uhry
www.mattuhry.com
Anders Holck
05-16-2007, 03:46 PM
That's actually the god thing about the old lead batteries.
They allowed you to float charge them.
You could do a setup like this, just without the inverter http://www.dansdata.com/diyups.htm
Not that I would mess with that myself, but I know a few Sound guys that have a similar thing in their sound mixer cart. It allows the mixer cart to supply power to HDD, mixer, microports and headphone amp, uninterupted.
When they have mains power they plug in the cart and it charges while feeding the inverter, but at all times they can plug it out and the batterys are drained.
And those nerdy Audiophiles love the clean spike and hum free batterypower :-)