low power 12vdc lcd monitor

cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
I'm looking for a low power 12vdc lcd monitor (size not important but at least 14-15 inches). Google doesn't turn much of these, the ones I did find were 4000$ range made for marine applications. I'd like to pay under 400$ for a 15inch size monitor. What are the factors in this type of product? Is it the color that takes alot of watts? Or is it the fact that its LCD vs CRT (or does crt use even more?)).

When I plug a standard AC 120V monitor in my wall, I'm assuming it has a rectifier that converts the AC to DC for the electronics inside the LCD monitor, so why can't I find something in native 12VDC? Laptops must do it all the time but I'd like something for a desk. Thanks for any information.

Comments

  • LBergmanLBergman Solar Expert Posts: 42
    Re: low power 12vdc lcd monitor

    Just a quick point, but I don't think 12VDC is the native voltage for LCD monitors. The electronics likely use 1.8-5VDC with the back light probably requiring some different voltage, so DC-DC conversion would still be needed inside the unit. Even in a laptop, the battery voltage has to be converted to several different voltage levels.
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor
    LBergman wrote: »
    Just a quick point, but I don't think 12VDC is the native voltage for LCD monitors. The electronics likely use 1.8-5VDC with the back light probably requiring some different voltage, so DC-DC conversion would still be needed inside the unit. Even in a laptop, the battery voltage has to be converted to several different voltage levels.

    Thanks for pointing that out, so we could use a voltage regulator like a 7805 for example to convert from 12 to 5 volts dissipating the extra voltage tru the heatsink. However my goal is to find a monitor that uses 10 watts or less, is that even possible or realistic ?
  • LBergmanLBergman Solar Expert Posts: 42
    Re: low power 12vdc lcd monitor
    cizzi wrote: »
    Thanks for pointing that out, so we could use a voltage regulator like a 7805 for example to convert from 12 to 5 volts dissipating the extra voltage tru the heatsink. However my goal is to find a monitor that uses 10 watts or less, is that even possible or realistic ?

    Without a backlight, I think it's quite possible. The backlight could be the thing that breaks the "current" budget...maybe. I know with my LCD television, the 12VDC draw through my inverter varies from 9 to 18 amps by just adjusting the backlight level. My laptop does the same thing, but to a much lessor degree with its far smaller screen (a ~1amp difference over it's brightness range).
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    I haven’t seen then in 15 inch sizes but I haven't looked either. I would look at portable DVD players with screens built in or add on second screens. Also take a look at automotive / mini-van stuff. I have seen lots of screens for kids to watch TV from a single DVD player. Both of those should be made to run from 12v.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • jacobsjacobs Solar Expert Posts: 72 ✭✭
    Re: low power 12vdc lcd monitor

    I remember seeing a 15" lcd monitor powered by a 12vdc wall wort several years ago. It wasn't anything special like marine. It probably was at Costco or Sam's Club but I'm not sure. I'd watch eBay or check at computer stores and ask if they use a wall wart and if so what voltage the wall wart is.
  • BB.BB. Super Moderators, Administrators Posts: 31,061 admin
    Re: low power 12vdc lcd monitor

    Just remember "wall wart" type 12 volt systems is that they many times do not like the ~10.5-15.5 volt range of a solar PV system (they may work better with a car where the voltage is around 13.6-14.2 volts).

    And, 7805, plus other "analog" regulators are not energy efficient... They "burn off" the excess voltage as heat--so they do not save any energy. For example, converting from 14.2 volts (charged battery) to 5 volts (with a 5 watt load) would require the regulator to dissipate:

    (14.2v-5v)
    * 5 Watts = 9.2 Watts of "lost" power
    5 volts

    Switch mode power supplies (buck, boost, etc.) are much more efficient when converting voltages (and currents) from one level to another. But can be more expensive and difficult to implement--the above example would have wasted less than ~0.5 Watts of power as a properly designed and sized switch mode power supply (as with anything electronic--it all depends on the application, needs, and volume).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,021 ✭✭✭✭✭
    Re: low power 12vdc lcd monitor

    Most smallish LCD monitors have wall wart or Brick on a String type powersupplies. I'll look up mine when I get home.

    Most likely, you will be better off using a small pure sine inverter to power the finicky electronics. The power distribution of 120VAC can't be beat, so if your monitor is pulling
    I know with my LCD television, the 12VDC draw through my inverter varies from 9 to 18 amps by just adjusting the backlight level.

    18 amps, that's going to be a hefty 12V cord for it.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: low power 12vdc lcd monitor

    Got a 15" Planar LCD that has an 12V 4 amp wall wart. Mod # PL 1500M.

    Here is one on fleabay:
    http://cgi.ebay.com/Planar-15-LCD-Monitor-PL-1500M-Screen-Computer-Flat_W0QQitemZ180313917375QQihZ008QQcategoryZ74931QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    4 Amps at 12vdc? if P=E x I that would mean it generates 12 x 4 = 48 watts?? I'm sure i'm wrong on that.. help me out here..
  • BB.BB. Super Moderators, Administrators Posts: 31,061 admin
    Re: low power 12vdc lcd monitor

    Yes and no...

    Yes, your math and basic assumptions are correct.

    No, in the sense that many devices do not use their name plate ratings...

    For example, many ratings have maximum current and maximum voltage listed... However, for many devices, they are "constant power" devices (many electronics and motors)--So, at minimum voltage (of say 10.5 volts) it will use maximum current (example: 10.5v*4amps=42 watts). At the other end, of the limits, high voltage--the current may be less (example: 42w/15v=2.8amps, but nameplate may look like; 4a*15v=60w vs 42 watts actual).

    Other examples are devices that use power in cycles (like a refrigerator), or use at different levels (fridge in hot weather vs fridge in cold weather, monitor back-light on high vs low, washer mostly empty vs mostly full).

    In the end, you usually will have to measure the actual current/voltage/time profile for your needs and plug those into the equations.

    And, the amount of sun you gather can easily vary by 10%-20% over time (weather patterns, pollution, etc.). So, getting "too accurate" does not help much either.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    In my search so far I found a viewsonic 15.6" monitor that uses 15 watts.. thats pretty good no?
  • mike95490mike95490 Solar Expert Posts: 9,021 ✭✭✭✭✭
    Re: low power 12vdc lcd monitor

    Mines a 19" GEM LCD, 12V 4A power brick Brick is just barely warm, so I doubt it's pulling more than 2.5A @ 12V
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    Allright this is the monitor I've been telling you guys about.

    http://www.viewsoniceurope.com/UK/Products/LCDE2/VA1616w.htm#Specs

    Look under power consumption in the specs, 15W typical / 20 w max.. only problem is I cannot find it in north america, only europe area. Any of you know of a similar or lower power consumption lcd monitor comparable to this one available locally?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    cizzi,
    i don't think that will meet your needs when it says, input voltage: ac 100-240 50/60hz.
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    Pure sine wave inverter will be used as suggested by someone earlier.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    ok, my mistake. it will be higher power consumption overall due to the inverter requirements just to be sure you're are aware.
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: low power 12vdc lcd monitor

    Dumb question, do you have the computer yet???

    If not, look at a cheap laptop.
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    No I don't yet, just looking to see if I want to go ahead with this right now. The motherboard I'd use would be this one : http://www.winmate.com.tw/PPc/PPcSpec.asp?Prod=05_0005&Typeid=050301

    using only 0.5A @ 12VDC.. so I want to combine this motherboard with the lowest possible LCD monitor.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    i totally agree with ken because after you have gone through all of the trouble putting together a system that the premade package afforded by the laptops along with it's performances (including power draw) would be hard to beat. unless you have a specific need of hardware not typically found on a laptop, i'd say go with the laptop.
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    I agree too, its more for the whole design/research and doing it all myself satisfaction I get at the end of all of it.
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: low power 12vdc lcd monitor

    I you want to get really low power, look at the current netbooks. I have a Asus 8.9" and 10.2" Eee PC's. At idle, the 8.9" is 8 watts and the 10.2" is 7 watts.
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    and simply plug in it a pure sine wave inverter?
  • n3qikn3qik Solar Expert Posts: 741 ✭✭
    Re: low power 12vdc lcd monitor

    Most brand name laptops will offer some type of auto adapter. So then power it right off the battery and save 10-20% efficiency.
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    Where is Matt? He sells low power consumption computers, I think his server is even running from a 12v bank.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • cizzicizzi Solar Expert Posts: 109 ✭✭✭✭
    Re: low power 12vdc lcd monitor

    there's a few companies out there that allready do this.. solarpc.com is one I've found
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