24 inch Dell as field monitor

Brian Drysdale · October 20th, 2006, 07:43 AM

Quote:

Originally Posted by Carlos E. Martinez

Large CRT as field monitor?!?!

On a dramas or high end productions yes, anything below 14" isn't really much use on HD, but if you just want to see the framing the smaller LCD's are fine. Documentaries are different, you wouldn't want to carry a large CRT on those (9" CRT is about the limit).

However, CRT is still regarded as superior for making colour judgements. Although, for location stuff a number of people do use the Apple 23" and the Panasonic 17" LCD is getting good reports. One thing about LCD is that you really need to be on axis, you can't tell a thing standing off at an angle to the screen.

I believe the Apple 23" works on 24.5 volts DC as well as AC.

Carlos E. Martinez · October 20th, 2006, 09:14 AM

Quote:

Originally Posted by Brian Drysdale

I believe the Apple 23" works on 24.5 volts DC as well as AC.

Yes, you're right: 24.5VDC it is.

Couldn't find what are the current demands for the 20" and 23" types, which is probably lower for the former.

John Mitchell · October 22nd, 2006, 02:39 AM

Most LCD monitors would likely run on DC internally - this would explain the lesser power demands on battery/DC as there are no losses in the AC/DC conversion.

Christopher Johnson · December 14th, 2006, 05:04 PM

Right the LCDs (and I like my Dell 24" thank you) are great for detail and focus judgments, but NOT color and black levels.

-Christopher S. Johnson

Justin Deming · December 16th, 2006, 09:52 AM

Vincent asked how this works

a JVC field monitor which runs on both AC as DC.
AC: 120v x 0.9A = 108 watt
DC: 12v x 4.3A = 51.6 watt

Well, the answer is that the transformer, and diodes in the power adapter turn the AC into DC at a cost. The AC adapter in this case will consume 108 watts of energy, while putting out the required 51.6 watts of 12 vold DC. No magic, the adapter just turns 51.6 watts of the power into DC, and the other 56.4 watts become heat.

That's why I hate using inverters. All electronics use DC on the inside, so if you power the AC adapter with an inverter you waste a ton of energy. In that scenario you take a huge DC battery, lose about 50% converting DC to AC, then power an AC adapter to convert it back to DC and lose another 50%. In the above setup, it would use 200+ watts from the battery, and deliver 51.6 to the monitor.

Also there is the issue of quality, low quality inverters can introduce noise into the power. This can stress the components causing a shorter life, and of course make problems in your audio.

So, I highly recommend the AB or IDX batteries. They will make the whole setup simpler, more effecient, and lighter!

That's all I can help with though, I have never adapted them like this, but I'm sure it can be done.

Carlos E. Martinez · December 16th, 2006, 10:43 AM

Quote:

Originally Posted by Justin Deming

All electronics use DC on the inside, so if you power the AC adapter with an inverter you waste a ton of energy.

That's almost true in most cases. I am not so sure how LCD monitors work there, but CRTs needed AC.

If LCD monitors work internally off DC only, then you can find out where that supply point is and feed it with DC from the outside.

No doubt you can do that with electronics, which usually feed off 5 to 12VDC, or some +/- version.

But I am not sure about LCD screens. What do they need?

December 14th, 2006, 05:04 PM	#19
Christopher Johnson New Boot Join Date: Sep 2006 Location: Los Angeles, CA Posts: 14	Right Right the LCDs (and I like my Dell 24" thank you) are great for detail and focus judgments, but NOT color and black levels. -Christopher S. Johnson

October 22nd, 2006, 02:39 AM	#18
John Mitchell Contributor Join Date: Jul 2005 Location: Sydney Australia Posts: 873	Most LCD monitors would likely run on DC internally - this would explain the lesser power demands on battery/DC as there are no losses in the AC/DC conversion.

December 16th, 2006, 09:52 AM	#20
Justin Deming Regular Crew Join Date: Mar 2006 Location: Minneapolis, MA Posts: 84	Vincent asked how this works a JVC field monitor which runs on both AC as DC. AC: 120v x 0.9A = 108 watt DC: 12v x 4.3A = 51.6 watt Well, the answer is that the transformer, and diodes in the power adapter turn the AC into DC at a cost. The AC adapter in this case will consume 108 watts of energy, while putting out the required 51.6 watts of 12 vold DC. No magic, the adapter just turns 51.6 watts of the power into DC, and the other 56.4 watts become heat. That's why I hate using inverters. All electronics use DC on the inside, so if you power the AC adapter with an inverter you waste a ton of energy. In that scenario you take a huge DC battery, lose about 50% converting DC to AC, then power an AC adapter to convert it back to DC and lose another 50%. In the above setup, it would use 200+ watts from the battery, and deliver 51.6 to the monitor. Also there is the issue of quality, low quality inverters can introduce noise into the power. This can stress the components causing a shorter life, and of course make problems in your audio. So, I highly recommend the AB or IDX batteries. They will make the whole setup simpler, more effecient, and lighter! That's all I can help with though, I have never adapted them like this, but I'm sure it can be done.