How To: Bus Electrical Systems - DC

[Les Lampman]

This is the start of the new "How To" section...Under Construction!

[Tritay]

I have a Converter. How do I set it up to run a TV and a DVD player without getting an inverter?

[Winchesterman50]

Sorry you can't
Converter is used to convert 120VAC to 12VDC
Inverter is used to convert 12VDC to 120VAC

Dave

[Dan-O]

Unless you get a 12VDC Tv and DVD player (either sep or you can get them in one unit) They are about 50 to 100$ more than your standard 120VAC comparable units. I have read that in some cases the power consumption on the DC units is a bit less than the comparable AC conterparts, so that may be something worth looking into as well.

[CAMO-MONSTER]

I HAVE ABOUT A 32" TV AND I DON'T THINK THAY MAKE A 12v IN THAT SIZE.

BUT I WOULD LIKE TO SWICH MY COMPUTER TO 100% 12v.
DOES ANYBODY HAVE ARY HELP WITH THIS ????


CAMO-MONSTER

[Ryan Grimm]

You might want to contact a computer modder or hacker, try you r local computer repair places. They can put you in touch with a modder who changes stuff around. IIRC, most computers use a power suppl/converter to reduce wall 120VAC to lower voltages used by the equipment.

BTW, you can LIQUID COOL most computers, which eliminates both fan noise (no more fan!) and the power drain that the fan would cause...one less parasite!

[lornaschinske]

We have a 20" Sanyo Vizon LCD television. it plug into a standard AC outlet. BUT it uses an AC to DC converter "brick". In reality, the television is a 12vDC unit. The brick had developed problems and no longer will power the TV (we think). I want to try a direct hookup but need to borrow the battery off the cart (it's the starter battery from the bus). Since we can't use the television anyway, I'm not concerned if we blow it up. Several folks on the RV forum have looked and realized their LCD TV's are powered by 12vDC and are now powering them directly off the batteries. Maybe I can get David to pull the battery this weekend and we can try it.

I planned on powering the TV, lights and possibly computer off a small inverter. I know the POS Onan generator in the Class C wasn't smooth enough to power my desktop computer. Every time it surged slightly, the computer shut down.

[chev49]

I do think they now make 32 inch tv sets in 12v. i have been looking for a tv for my bus, and i think i saw one that size on the internet somewhere... The 52 inch plasma one i have is taking up too much room...

[greaper007]

To the computer question. Go to a site called mp3car.com, it's dedicated to computer builds inside cars. Which was a really cool thing about ten years ago before iPods or iPhones, now you can get all your music and videos off your phone so it's not so exciting. Anyways, they have a whole section on 12vdc power supplies, and there are a few commercially made ones. They used to be rather expensive, like $200 or so, but I'd imagine they've come down in price now.

The advantage of the 12vdc power supply is that your computer uses 12vdc, and normally has to convert 120vac from a wall circuit. Throw an inverter and a conventional power supply into the mix and you have a very inefficient system, a 12vdc supply is a great idea for an application like this.

[CAMO-MONSTER]

We have a 20" Sanyo Vizon LCD television. it plug into a standard AC outlet. BUT it uses an AC to DC converter "brick". In reality, the television is a 12vDC unit. The brick had developed problems and no longer will power the TV (we think). I want to try a direct hookup but need to borrow the battery off the cart (it's the starter battery from the bus). Since we can't use the television anyway, I'm not concerned if we blow it up. Several folks on the RV forum have looked and realized their LCD TV's are powered by 12vDC and are now powering them directly off the batteries. Maybe I can get David to pull the battery this weekend and we can try it.

I planned on powering the TV, lights and possibly computer off a small inverter. I know the POS Onan generator in the Class C wasn't smooth enough to power my desktop computer. Every time it surged slightly, the computer shut down.

and news on your attempt with the tv?
what size onan do you have?
cause i have a 4k.

[Redbear]

I HAVE ABOUT A 32" TV AND I DON'T THINK THAY MAKE A 12v IN THAT SIZE.

BUT I WOULD LIKE TO SWICH MY COMPUTER TO 100% 12v.
DOES ANYBODY HAVE ARY HELP WITH THIS ????


CAMO-MONSTER

To the computer question. . . . . . The advantage of the 12vdc power supply is that your computer uses 12vdc, and normally has to convert 120vac from a wall circuit. . . . .

Older desktop power supplies had regulated +12 volts, - 12 volts, and +5 volts coming out. Newer computers run at +3.3 volts to the processor instead of +5 volts. Most of the computing is done at +5 or +3.3 volts, I think. If you open the cover on a desktop, the AC power supply should have a sticker with the output voltages and currents, or else get the OEM model number, and search the web for specifications.

Laptops I have seen usually charge the batteries from about +18 volts DC out of the charger, and would need a DC-DC step-up converter to run them on mobile DC. Getting a small (~100 watt) Radio Shack or similar inverter to power the AC charger is usually simpler and cheaper. Just turn off/unplug the inverter when not in use.

Providing the -12 volts for a desktop is the toughest, as you would need a DC-DC converter, and cannot just regulate down the positive battery voltage. But I think the -12 volts was only used in old serial and maybe parallel ports, where the digital ones and zeros were sent as plus and minus instead of on and off. A 9-volt transistor radio battery might be enough to supply the reverse polarity if you needed that for a port. The new USB ports have 5-volt power, but I don't know the signal voltages. I would suspect a desktop would run just fine on the +5 and/or the +3.3 volts, or maybe that plus the +12.

Building step-down regulators to run a desktop off of 12 volts is somewhere way, way down my list of theoretical projects for when I get a "round tuit." But if I get to it at all, I will likely only get as far as converting an ancient IBM Thinkpad laptop with a failing display that sits in my junk box. I would use it as a CPU with external monitor, as I know from experience that 12 volts to the battery clips will run one of these units. I can get an adapter that uses a camera memory chip to replace the ancient hard drive for storage.