12v TV

basewindow
basewindow Solar Expert Posts: 63 ✭✭
Hi all. I have a 12v Tv. Plugs into AC mains but has a transformer which down converts to 12v at 3.9A DC. At least that is what is written on the transformer. Now i am considering running this directly from my 12v solar setup. Only problem im seeing is that with solar charging there is a fair variance in the voltage ie. 12.x up to 14.6 in my case.
So question is am i going to destroy my Tv if its up around 14.6v or do these units usually have a bit of voltage tolerance? Anyone had any experience with 12v? Any thoughts? 
Cheers All.
Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    That is a major issue with off grid solar--A 12 volt system can range from 10.5 to 15+ volts. Many 12 volt adapters are designed for an automotive system with 12.0 to 14.2 typical range of voltage.

    Will it damage your 12 volt converter--Really do not know. There have been reports here of folks losing their 12 volt car adapters when operated on their solar power system.

    That is one reason why I suggest using a small AC inverter (like you have) to power from AC mains voltage. The AC inverter manages the DC side, and you have a pretty rugged AC appliances running from the (regulated) AC inverter at 85-95% inverter efficiency.

    It does run into the old risk/reward question. If this was an old TV you did not care about, why not try it. If it is new/not cheap, then perhaps it is not worth the risk. If you do not exceed 14.6 volts (AGM batteries, no equalization)--You might be OK (not much worse than typical automotive use).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    For $9 you can be sure that you won't have a problem.  Probably with better efficiency than a double conversion.

    http://www.ebay.com/itm/DC-DC-Current-Boost-Buck-Converter-Power-Voltage-Regulator-6-35V-to-1-35V-5A-/321795754199

    I am available for custom hardware/firmware development

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Buck boost converters are about the same efficiency as an AC inverter (88-90% for the buck boost converter on EBay).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DConlyGuy
    DConlyGuy Registered Users Posts: 80 ✭✭
    i had the same problem with my 12 volt computer, i fixed it with a step up converter to19 volts which my monitor uses and  then used a step down to 12 volts for my computer and now i have a very stable dc system now. 
    600 watts of solar panels,Epever 30 mppt , 2 PWHR12500W4FR battery's in 24 volt setup
  • basewindow
    basewindow Solar Expert Posts: 63 ✭✭
    Forgot to mention this TV is for a caravan (Australia terminology) which I have permanently set up next to the shack mainly for the teenage kids when they visit. Apparently they don't want to watch the same things as me.
    Yes I could put another small inverter in there but it was another point of failure I ideally wanted to avoid if possible and I guess also with the dc-dc converter/regulator. However that one in the link is certainly cheaper than the ones I was looking at over even including shipping.
    TV is 22" modern flat screen but wasn't expensive, but I don't want to kill it either.
    I actually tried it direct connect yesterday with solar switched off and battery at 13.6v and all seemed OK. I guess for the time being they can use it at night when the battery voltage it lower.
    I will probably look at something like the item in the link for the future.
    Thanks for the comments.
    Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    You could see how big a motor cycle battery you need for the TV and dedicate it to that use and charge every 4 days or so...?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • basewindow
    basewindow Solar Expert Posts: 63 ✭✭
    Ive already run a line out there for the lights and ive already got way more battery than i need for the shacks power use, so i may as well use what ive got. Hopefully the kids wont be watching too much TV during the day when the voltage is high. Am i kidding myself?? Lol.
    Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
  • basewindow
    basewindow Solar Expert Posts: 63 ✭✭
    Quick question. I bought a buck converter 'tusotek' as per the link. Didn't come with any instructions. I asume you adjust the output voltage with the screw on the blue mounting?
    Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
  • Aguarancher
    Aguarancher Solar Expert Posts: 315 ✭✭✭
    edited November 2016 #10
    yes, according to the pic on the website
  • basewindow
    basewindow Solar Expert Posts: 63 ✭✭
    Thanks. The one I bought doesn't have that picture in its description and is a slightly different format but has the blue mounting and screw.
    Cheers.
    Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
  • Aguarancher
    Aguarancher Solar Expert Posts: 315 ✭✭✭
    the picture was taken from the link above where you said you purchased it from. let us know how it works out for you..
  • kc8adu
    kc8adu Solar Expert Posts: 50 ✭✭✭
    every 12v tv i have seen runs fine 10.5-16v.
    all the internal supplies are from buck converters.
    which includes ccfl drivers.i have several sets that i tested and the current drops as voltage is increased.
    the one i fixed up that was a curb find has 25v caps on the dc input.
    lots of margin.the output caps on the converters were trash.and thats why it hit the curb.
    the only parts that would suffer from high input are linear regulators and those are off the +3.3 and +5 bucks.so are shielded from high input voltage.its a bit different with security dvr that use 3.5" sata hdd.
    the +12 to the drive comes right from the input.
    solution is a 2.5" notebook drive that does not use +12.
    the cameras are very forgiving as well as they are speced 24vac/12vdc.
    i have several installations running 4 years now.
    so dont worry about it.