| Author |
Message |
James Taylor
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 15, 2005 - 3:17 pm: | |
Most 17 in lcd tvs I have looked at are 110v that convert down to 12V my question is can you make these work on 12v only so you do not have to use the inverter thanks for any information you can give |
KC Jack
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 15, 2005 - 6:19 pm: | |
If you look at the transformer that converts from 110 to 12, they are usually 12 volts REGULATED. Your 12 volt bus system will fluctuate from at least 12-13.5, probably more. No, I would not use 12 volts from a bus system. There are devices that will regulate the 12 volts drawn from the bus system but I am not familiar with a commercial product.
Jack in KC |
Don/TX
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 15, 2005 - 6:53 pm: | |
I just put mine on a small inverter, cost only a few dollars, works fine. |
Ed Jewett (Kristinsgrandpa)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 15, 2005 - 7:29 pm: | |
Put a good voltmeter on the regulated power supplies. The actual voltage will be a lot higher than the stated value. The load draws down the voltage a lot, but even with the load on them most are high.
Gary Stadler can explain this a lot better than I can.
Ed |
Jojo Colina (Du1jec)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 16, 2005 - 2:25 am: | |
I have been powering a 17 inch Samsung LCD panel from my coach 12v for two years now. The power circuits in these things will withstand a +/- 10% variance in voltage as designed. Almost all circuit design will allow for such variance in input voltage. I know in practice that they will work with much more variance than that.
You should make sure that your voltage regulator is set not to exceed 14 volts. The downside of overly high voltage will be that the set has to dissipate more heat in regulating the incoming voltage to what it needs. Most circuits in your LCD TV will be 5 or 3.3volts except for the LCD Backlight which will be powered by a small inverter. While higher than rated voltage input (within reason) will theoretically will shorten the lifespan of the unit in question, it will be arguable whether it is going to significantly decrease your ROI on the unit.
Power supplies have more voltage than sticker rating due to the fact that you can always dissipate excess voltage as heat with a simple Voltage Regulator, but you cannot step up the voltage without more cost and complexity. |
David_
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 16, 2005 - 5:51 am: | |
KC Jack is right about the 12V in your bus fluctuating. You are more likely to see 12V-14V, which your LCD is not going to like.
However most LCD displays do not dissipate more than 1.5 Amps of current, which is not that hard to regulate. If you have a friend who knows something about electronics, ask her to whip up a regulated power supply using a 78L12 integrated circuit. The circuit will use less than 5 components and cost less than 10 USD.
If your LCD draws more current, you could replace the 78L12 by one of the more efficient switched mode regulator IC's, but that'll take a bit more work.
Good luck. |