Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 27

Thread: Help, trying to convert AC monitor to use DC.

  1. #11
    Admin. Linux loser.
    Auto Apps:loading...
    Bugbyte's Avatar
    Join Date
    Sep 2004
    Location
    Corning, NY
    Posts
    7,359
    Blog Entries
    2
    Quote Originally Posted by digitalmayhem View Post
    So if I understand correctly, the power is rectified to dc and then converted to two different voltages using the regulators? So I would want to find the voltage after the rectifier and feed it what it wants and let it regulate that current into whatever it needs? Also, if I do F up this board, I can replace it for $30.
    The regulators keep the power from exceeding a certain voltage limit. The transformers are what steps it up/down.

    It looks like the transformers are after the rectifier and before the regulators. If true, that means a single DC voltage is supplied and then stepped up/down by the circuitry so you could theoretically feed it a single DC voltage and it would work.

    *IF* I am right. Which I may not be.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
    -Find out about the new iBug iPad install?
    -Find out about carPC's in just 5 minutes? View the Car PC 101 video

  2. #12
    Newbie
    Join Date
    Jul 2008
    Location
    Detroit
    Posts
    48
    So I do want to check the voltage at where I labeled as "dc out" at the positive and negative terminals?

  3. #13
    Maximum Bitrate JimmyFitz's Avatar
    Join Date
    Nov 2005
    Location
    Austin, Texas
    Posts
    735
    Quote Originally Posted by digitalmayhem View Post
    So I do want to check the voltage at where I labeled as "dc out" at the positive and negative terminals?
    Start there. If it is 12V you are golden. That is not likely. Chances are it is a fairly high DC voltage so be careful. The clue about that is that the nearby capacitor is only 100uF but at 450V. Be careful not to get your fingers in there, it may bite!
    ~Jimmy

  4. #14
    Newbie
    Join Date
    Jul 2008
    Location
    Detroit
    Posts
    48
    It read 165 volts before my dumbass tried to measure the amps and blew the fuse on the board. I'm an idiot.

  5. #15
    Variable Bitrate Arrow's Avatar
    Join Date
    Feb 2006
    Location
    West Lafayette, IN
    Posts
    288
    The ammeter creates a short across the leads. It's almost the same as just taking a wire and shorting out two points. Don't do that.
    Anyways, here's what I think the different parts are. Everything that I pointed out is an AC component except for the regulator and the rectifier... That I'm thinking that since there are voltage multipliers on the board, that the backlight may run on the AC.
    Attached Images Attached Images  

  6. #16
    Admin. Linux loser.
    Auto Apps:loading...
    Bugbyte's Avatar
    Join Date
    Sep 2004
    Location
    Corning, NY
    Posts
    7,359
    Blog Entries
    2
    See? There you go - I think Arrow may be right. If that's a filter, not a rectifier, then it is AC up to that big capacitor for sure. Looking close at the ~DB50, right near the base of the cap, I think that indicates that you have AC power at that point. Did it read 165 volts AC?

    Those big things attached to heat sinks are avalanche diodes, if my googling is correct. They are supposed to protect from over voltages.

    With the voltage regulator way up there on the upper right, I think Arrow is right about the backlights being powered some other way - probably AC, which would make running this thing on DC only difficult.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
    -Find out about the new iBug iPad install?
    -Find out about carPC's in just 5 minutes? View the Car PC 101 video

  7. #17
    Maximum Bitrate JimmyFitz's Avatar
    Join Date
    Nov 2005
    Location
    Austin, Texas
    Posts
    735
    D850 is definitely a bridge rectifier. C854 is a filter capacitor. Everything past that uses DC. The backlights need a high voltage and the logic circuits need a low voltage, hence there are at least two regulator circuits. Let's remember the purpose of the OP's question: can the monitor be run on DC if it is put in past the place where it is converted from AC to DC? The answer is yes it can, IF you put 165V in. That is not practical to do in a 12V auto environment.
    ~Jimmy

  8. #18
    Newbie
    Join Date
    Jul 2008
    Location
    Detroit
    Posts
    48
    my multimeter was in dc mode. typing from a cell phone.

  9. #19
    Admin. Linux loser.
    Auto Apps:loading...
    Bugbyte's Avatar
    Join Date
    Sep 2004
    Location
    Corning, NY
    Posts
    7,359
    Blog Entries
    2
    Well, right there you have a problem, then. Since you can't supply 165 volts DC, you're going to have to figure out the various DC voltages you need.

    If you need AC to power the inverters, now you're talking about replacing the inverter(s) and CCFL's plus figuring out what voltages you need to operate the monitor.

    Going back to your original post, you said you got noise from using an inverter. It may be easier to get that noise out of the system than go with DC power. Was it a cheap inverter? Was it grounded properly? Did you run the power wires near the audio wires? Those are some of the problems that cause noise in the system.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
    -Find out about the new iBug iPad install?
    -Find out about carPC's in just 5 minutes? View the Car PC 101 video

  10. #20
    Newbie
    Join Date
    Jul 2008
    Location
    Detroit
    Posts
    48
    It seems your are exactly right, if I want to use this monitor I will have to use an inverter, after replacing the fuse I blew and crossing my fingers that I didn't destroy the board. The inverter I have now is a Xantrex 1000w. It was being powered by a 4 gauge power wire and 4 gauge ground. I believe the ground is good. Anyhow, today I was lucky enough to be given the gift of about 25' of welding wire (I work in a steel fab plant). Pretty sure it's 0 gauge, but it's old and greasy and can't find the size written on the insulation. I am going to test the inverter with two short lengths directly to the battery and see if the buzzing stops. If it does that means my goal is attainable. If it still buzzes on a 12" power and ground, I will have to go to plan B, not sure what that is yet. I know plan B is going to involve $$$. :-)

Page 2 of 3 FirstFirst 123 LastLast

Similar Threads

  1. dc - ac power inverter
    By dasaint80 in forum Power Supplies
    Replies: 3
    Last Post: 12-10-2005, 03:16 PM
  2. Possible to turn a DC Toggle switch into AC???
    By Defiler in forum General Hardware Discussion
    Replies: 5
    Last Post: 07-05-2004, 08:29 PM
  3. AC or DC power supply w/ tablet pc?
    By gutterslide in forum Power Supplies
    Replies: 2
    Last Post: 04-07-2004, 03:12 AM
  4. dc or ac power supply
    By qball008 in forum Power Supplies
    Replies: 0
    Last Post: 05-16-2002, 10:22 PM
  5. Need help finding an AC to DC power adaptor
    By Squeezer in forum General Hardware Discussion
    Replies: 3
    Last Post: 12-29-2000, 12:27 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •