i connect the wire needed and when i test it, the screen show only some verticle black lines, wht's wrong with my modding? and i want to use the PSU to supply 7V for the LCD, how should i do?
get a car kit(cigarette car power adapter) and mod that!! some body has done it alredy http://forums.bit-tech.net/showthread.php?t=62664
DO NOT USE 12v and 5v from the PSU to power the LCD. The ground from the RCA connector might be connected to the ground for the power in the LCD. If you tried to use the 12v and 5v for ground, you would end up passing 5v through the RCA ground and burn your video card or what ever source you have for input. Do the smart thing and use a resistor for your project. That is the safest way to go. For all individuals that suggest solutions to problems, please consider the effects of your solution prior to suggestion. You just might F'up some one's project in the process due to your neglect. Please don't just post the first solution that comes to mind or whatever post you ripped your info from without proper thinking.
w143r - You cant use a resistor for this becuase the voltage depends on current * resistance. Niether of them are constant on semiconductor stuff (afaik). The lcd needs 7< and <8v to run, anything in between is fine. You need to drop atleast 4v (or less depending on how crap your psu is ). Best way is to use IN5401 diodes in series. These are rated to 3A, as the screen only draws 600mA these are plenty. The smaller IN4001 might get a little hot as its rated to 1A. Adding these in series will give an 0.7-1.2v drop in supply voltage depending on the current (600mA) being drawn. I cant remember right now but id guess about 0.8v drop. By adding these in seires, you lower the supply voltage. Idealy you would use 4 or 5 of these diodes, this would give you around 7.5v bnut you SHOULD check before trying it on an LCD (use a multimeter!!) and to check you need to be drawing around 600mA or your testing wont mean anything! Or you could use a LM317T regulator circuit, but it has more parts and diodes are just easyer... the only advantage is the lm317T would keep the voltage the same indepemndant of the output from your psu, wheras any small changes from the psu will go past the diodes and possibly under/over volt your screen.
so i cant use 12v & 5v of PSU to supply 7v for the LCD? i hv read the old post, ppl said the LCD consum 900mA, it take 900mA or 600mA ? i need add a 5 ohm resistor(when 900mA) to 12v in order to get 7.5v ?
In actuality, you can and should use a resistor for the supply voltage. By using diodes, you run into the issue where if you turn down the back light, the amp draw drops resulting in change in voltage. This has a higher potential of F*ing up your LCD than a resistor would. Now as for the inconsistency of the supply voltage. We are assuming that he wants to tap into his PSU, which we would assume to supply Consistent current and amps, or else EVERYTHING fries and the LCD is the least of his worries. Lastly, I have tried this method and it works beautifuly. Only one part to buy and solder and you're ready to go. Using a LM317T circuit is optimal, but that would be pricy also. It's your choice.
People say a lot of things. My LCD takes a 7V and 2A, which is no where near what they said. But again, every LCD is different. Now, the current drawn (amps) only relates to how much current is necessary to power the unit. You only worry about this when you buy your resistor. Simple calculation: Input Voltage - Resistor = Resulting Voltage Current Drawn * Voltage = Wattage To get 7.5V you need a resistor that is rated 4-5 Ohms with 5 Ohms being on the safe side and 4.5 being perfect. Each resistor has a wattage label on it. It determines how much current can the resistor handle before heating up too much, and yes they do heat up quite a bit. To calculate this, take resistor Ohm and multiply by the amps drawn. For my LCD the calculations would be as follows 12 V - 5 Ohms = 7 V 5 V * 2 A = 10W I need a 5 Ohm resistor that is rated at 10W for my LCD to work, and it did work.
ic, thx how should i connect after i got the resistor? is it 12v --- resistor--- pin2 of 12pin connector (white wire) ground -----------pin1 of 12pin connector (blue wire)
mine, there is a ST35 for AV-in, i cant find a cable that is "ST35 to S-video", sb told me to use "ST35 to RCA" + "RCA to S-video", hvn't try if this method work.
the problem with the image on yours is the scren timings. Use serios (pal) timings (or ntsc) in the states and fiddle with the vertical refresh. I havent managed to get the full res working yet, only pal.
is it i need to use a normal mon 1st then install powerstrip, change the res to 640X480 & switch on the csysn, and finally reboot & change the PSone LCD?
actually that would be 17 volts, it would need to be +12 and + 5 to get 7 volts. that it unless my understanding of electronics is crap
1well some people have cards w/o rca and u get a better picture with vga, 2some people are noobish and dont wanna blow there $80 lcd so they check here, here being a place to learn and help
well the first part is wrong u get 12v because a ground is a ground, the second part is right and since posting i learned the correct way
