I recently bought a Koss DVD player for my car and have done some research on it and found out that the AC adapter that it comes with should run at 12v but it actually puts out up to 16v, which makes the DVD player very hot (I'm afraid it will eventually burn the player up). Right now I have it plugged into a power converter (AC -> DC), but I realized this: if the player runs at 12v and the adapter is a peice of crap, why don't I just cut the adapter off and plug the wires directly into my battery and ground, (using a fuse of course)? Does anyone know any reason why I can't/shouldn't do this? It would be great to not have to have to use the power inverter.

 

The only reason I could see to not do it would be that your car's electrical system does not produce an exact 12v. IUn fact, it's probably more along the lines of 14 or so normally, and will fluctuate by a couple volts here and there. Have you thought of getting a dc->dc converter? It will regulate the additiional voltage spikes and supply a clean dc output to whatever you need it for.

 

Now that we see DVD player for the price of $69.00 it becomes hard to want to keep buying all these silly adapters. The fact is this your car will never produce 16V unless you have a serious voltage regulator problem. Also your DVD player should be able to handle any voltage changes that occur in your car.

 

True, if it's designed to run at 16v (which is what the factory AC adapter is if I'm understanding you correctly), then I think you would run a better chance of ruining it by trying to run it at 12v.

I didn't catch the 16v part the first time, but the fact still remains that even if it was 12v, your car doesn't produce a clean 12v to reliably power something like a DVD player meant to be used with a wall wart without a dc->dc converter.

 

If you bought a car DVD player hook it up let it fly! It is made to deal with all the voltage changes in your car. I have had so many car DVD players and I have not had any of them fail due to voltage. I will say some have just been cheap crap but none have had any voltage problems.

 

a cars electrical system (when running) puts out 14.4 volts (industry avg)...

now, a 16v product running off of a 14v (or 12v if vehicle is off) will actually work harder and not last as long..(will draw more current and run hotter)

its called ohms law,

any serious car audio person knows that upping the voltage (within designed levels) makes the system perform better...

 

Agreed, electronics designed specifically for automotive use are, well... designed for automotive use and have regulators, filters, etc built in to compensate for this stuff. pdrizzle-> personally, I would just go get a dvd player made for your car, hehe. You may end up spending just as much to make your existing one work correctly/reliably.

 

Wow really interesting, thanks. I thought the post said his DVD adapter should be 12V but is reading 16V. Not "16v product running off of a 14v or 12v"

Ohms law V=I X R
Ohm's Law defines the relationships between (P) power, (E) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.

 

Thanks for you guys' input. Let me clarify about the voltage: the DVD player is supposed to run at 12v. It came with a AC adapter that is supposed to power it at 12v. I've been reading forums about it and people are complaining that it gets hot after minimal use, which I have experienced too. One person on the forum said that he tested the AC adapter (I'm guessing with the DVD not plugged to it) and found that the AC adapter is actually pulling 16v instead of 12v, and that he replaced the original wall adapter with a generic 12v AC adapter from WalMart and that fixed his heat problem.

So, what I'm trying to figure out is if I should go through the time, effort and cost to purchase a new wall adapter (12v), mount a DC to AC power inverter, and run the home DVD player off of the inverter and the inverter off of the battery; or could I save some of that headache and just cut off the wall part of the adapter and take the power wire, run it to my battery (or fuse box) and ground the ground wire. I heard a few people mention some extra equipment I might need, any details is appreciated.

As far as buying a DVD player for the car, I'd much rather fabricate/rig something out of cheaper home equipment than pay a premium for a car one (call me cheap, but that is my goal). I've already got a pretty nice LCD monitor and I don't want the DVD player visible, so I'm going to relocate the IR sensor for the DVD remote and mount the compact player in my glove box. My buddy has done something similar and it works really well for him for a very little cost.

 

$69.00 is a premium?

 

lol, are you fishin for arguments or what? ;)

 

i think his home dvd was 69.00 not the car one. maybe i'm wrong.

 

oops. kinda mis-read that.. :oops:

but it is still true that a little more voltage will decrease the current (the current causes heat)

thats why a lot of amps are rated at 12v then 14v and the 14v output is greater...

but, sorry for mis-reading

 

Scions (and most other cars) have 12.5V electrical systems. The alternator charges @ a greater voltage because if it didn't, the battery could not charge. There needs to be a difference of potential for current to flow. Remember that there is a difference between a power-source output without a load and with. Measuring voltage sag is almost impossible with a digital volt meter due to it's sample rate. You'll need one with a "Dip Hold" feature (happen to have one) to really get a sense of it.
If a device is designed to operate on 12V DC, than it will operate on 12VDC no matter if it's form a "Wall Wart" or a car's battery.
Keep in mind that in the home, the supply voltage is greater than in the car so voltage sag is not a problem. In the car, it's not unusual for voltage to sag below 12V especially when there is a high-powered aftermarket stereo system. So the question is not will you have too much power, but rather will you have too little?
I would give it a try, you most-likely will be fine.

 

you are right, all the electrical systems in cars are desigend to work on 12v.

but my chargeing systems puts out 14.2v...
and upping the voltage reduces the current or reduces the load...

but if the voltage goes to far beyond the normal range then things blow up...

 

Boom12v, I've never seen a car DVD player for $69 (at least one that I would want to go through the trouble of installing). I'm not getting rid of my radio (I have the stock 6 disc MP3 with XM, which I love), I like having the cubby area below the A/C *****, and I have a sunroof so installing it overhead isn't an option either. I have amps underneath both seats so my only choice of hiding the DVD (which I want to do) is either in the glove box or in the trunk area. I'm going with the glove box for ease of install.

JLTD, thank you for your input. I will try it and see how it goes. When I bought the car it had a nice system installed and I'm not even sure where and what all of the equipment does. I know I have a 1 farad capacitor for my amps and I believe I have a voltage regulator (there is something attached to my firewall that comes from my battery and goes to my amps; it has a red button on it which I believe is a reset switch), so I know my stereo equipment is being taken care of (I've never experienced any lights dimming and the system romps with almost no hissing). I'm going to put inline fuses on everything and hope I don't burn any of my equipment up.

Thanks, guys!

 

As far as DVD players go the cost of them has come down so much. I have seen no fewer than 8 DVD palyers that range from $69.00 dollars to $75.00. Any of these are as good as a Koss (no offense).
If you like your radio by all means keep it. To each his own. We just finished a XB that we sponsored. The DVD paler was installed in the cubby below the AC controls. It fit great! Once it was inthe door to the cubby closed so you didn't see the unit from outside the car.

 

i've seen dvd's way cheaper than 69 bucks. wall mart has one for like 40, and radio shack has a really cool compact one (about the size of a small book) for under 35$

 

but are those car (12v) players
and are they worth putting in...

 

nope, we weren't talking about that, just the cheapest home dvd. thats what the guy bought. it just happens to have an power input of 12v.