دوست عزیز اغلب دی وی دی ها خروجی vga دارند اگر هم ندارند اگر بتونی rgb و v و h رو پیدا کنی میتونی وصل کنی اینم راهنما
[h=2]VGA to RGB + Composite Sync converter[/h]
First circuit is for connecting VGA card to video projector or a monitor which accept VGA card frequencies and has RGB + Composite sync input. This circuit has been succesfully used with Electrohome Projection Systems ECP 4100 data and video projector.This circuit is designed for converting normal VGA signals standard RGB signals and composite sync signal. The circuit is quite simple, because RGB signal ouput from VGA card is already standard 0.7Vpp to 75 ohm load.For sync signals there is a circuit which combines horizonal and vertical sync signals to form composite sync singals. The circuit is simply based on one TTL chip with four XOR ports, two resistors and two capacitors. TTL chip ws logical choise because VGA sync signals are TTL level signals.The sync signal combiner has a system to adjust to different sync polarities so that it always makes correct composite sync signals. VGA card uses different sync signal polarities to tell the monitor which resolution is used. This circuit adjusts to sync signal polarity changes in less than 200 milliseconds, which is faster than setting time of a normal VGA monitor in the display mode change.[h=2]Analogue composite sync signal converter[/h]
First circuit is for connecting VGA card to video projector or a monitor which accept VGA card frequencies and has RGB + Composite sync input (1 Vpp signal level, 75 ohm input impedance).
This picture is available in GIF and Postscript versions.Note: The circuit diagram does not show the wire giving power to IC1. The +5V power is connected to pin 14 and ground is connected to pin 7.This circuit has been succesfully used with Electrohome Projection Systems ECP 4100 video projector in many VGA and SuperVGA modes. The circuit have been also used succesfully with one old Barco video projector using my VGA to TV drivers to get the VGA card to generate suitable signal frequencies which that old video projector can handle.[h=3]Component list[/h]
C1 22 uF 10V electrolyticC2 22 uF 10V electrolyticR1 2.2 kohmR2 2.2 kohmR3 1.8 kohmR4 1.8 kohmR5 2.7 kohmR6..R8 47 ohmU1 74LS86 or 74HCT86T1 BC 547T2 BC 547[h=2]TTL level sync signal[/h]
Many computer monitors have been designed to accept TTL level sync signals. If you happen to own a monitor which uses TTL level sync signals the circuit above does work with with it, because the sync signal level from that circuit is not enough for the monitor. I have designed another simpler circuit for monitors which need TTL levels.
Note: The circuit diagram does not show the wire giving power to IC1. The +5V power is connected to pin 14 and ground is connected to pin 7.This circuit is basically the same as the first circuit. The only only difference is that the transistor driver stage have been left out from the circuit, because not so much driving capacity is needed and TTL levels signals from the IC are what is wanted. Because the 74LS86 IC directly drives the output without any further buffering, it is only suitable for driving high impedance (1 kohm or more) sync inputs.[h=3]Component list[/h]
C1 22 uF 10V electrolyticC2 22 uF 10V electrolyticR1 2.2 kohmR2 2.2 kohmU1 74LS86 or 74HCT86[h=2]Simple sync combining BOX[/h]
Sometimes you want to use a ready-made BNC cable made for connecting VGA card to high quality monitor. Those BNC cables have 5 BNC outputs with following functions:
Signal Function Color in cable---------------------------------------R Red RedG Green GreenB Blue BlueH/HV Hsync(+Vsync) BlackV Vsync White or Gray
Tha cables are usually built (should be built!) from high quality 75 ohm coaxial cable and 75 ohm BNC conenctors to guarantee good image quality. You can see a typical schematic of commercial VGA to BNC cable below:
This kind of cable can be used with monitors with 5 BNC inputs. But if you unfortinately have a monitor with RGB and composite sync inputs only, that cable might not be of any use, unless your graphics card can generate composite sync signals (this is not a standard option). If you cna get composite sync directly from graphics card, then it is enough to just connect the H/HV connector to the composite sync pinput of the monitor.If you are on unfortunate person who deos not have this kind of graphics card or your drivers don't allow using that option, then your only choice is to build a circuit which combines the separate HSYNC and VSYNC signals to composite sync. You can see this kind of circuit below.
[h=3]Component list[/h]
C1 22 uF 10V electrolyticC2 22 uF 10V electrolyticR1 2.2 kohmR2 2.2 kohmU1 74LS86 or 74HCT86[h=2]Connecting VGA to Sync-on-Green monitor[/h]
Some monitors use sync-on-green syncronization instead of separate sync. In that case you can't used my circuits directly. You have to modify those circuits to add Sync-on-Green capability. Generating sync signals to screen picture component is quite easy. I have not had any need for such a circuit, so I haven't designed such option. Check this article to get the idea what to add to my circuits. For more complete explanation how to deal with sync on green monitors, check the Sync on Green FAQ.[h=2]Building the circuit[/h]
The circuit is quite simple to built if you have basic skills in building electronic circuits. The electronics of the circuits can be easily built to a small piece of veroboard so no special circuit board is necessarily needed (I used this approach in my prototype). I have designed a circuit board for my VGA to TV converter and this same PCB design (GIF picture scanned at 300x300 dots/inc resolution, also available in zipped postscript file format) and component layout can be used with this project also. Note that there are some differences in connection of the IC U1 pins in PCB compared to the schematic, but the circuit built to this PCB fuctions in the same way.The circuit need well-stabilized power +5V power source (+/- 5%). The circuit takes less than 150 mA current, so you don't need a large power supply. If you don't have anythign suitable avalable, you can always use a small general purpose wall transformer and a small +5V voltage regulation circuit. Another option is to take the +5V power from PC using methods explained in my How to get power from PC to your circuits document.The wiring should be made carefully and 75 ohm coaxial cabling for picture signals should be used everywhere, especially if you are going to use this circuit with a high resolution monitor. Signals reclections caused by bad wiring can really mess up your picture quality. I would recommend using metal box, shielded cables and shielded connectors for circuit to keep noise and radio interference minimum.[h=2]VGA to RGBS converter component list[/h]
U1 74LS86C1,C2 22 microfarads, 16VR1,R2 2.2 kohm, 1/4 WR3,R4 1.8 kohm, 1/4 WR5 2.7 kohm, 1/4 WR6,R7,R9 47 ohm, 1/2 W R8 120 ohm, 1/2 WT1,T2 BC547BP1 15 pin SUB-D connectorOutput connector:75 ohm BNC connectors (you need 4 BNC connectors)Wiring:Red, Green, Blue and Composite Sync lines should bewired using 75 ohm coaxial cable.
Note: The circuit diagram does not show the wire giving power to IC1. The +5V power is connected to pin 14 and ground is connected to pin 7.This circuit is basically the same as the first circuit. The only only difference is that the transistor driver stage have been left out from the circuit, because not so much driving capacity is needed and TTL levels signals from the IC are what is wanted. Because the 74LS86 IC directly drives the output without any further buffering, it is only suitable for driving high impedance (1 kohm or more) sync inputs.[h=3]Component list[/h]
This kind of cable can be used with monitors with 5 BNC inputs. But if you unfortinately have a monitor with RGB and composite sync inputs only, that cable might not be of any use, unless your graphics card can generate composite sync signals (this is not a standard option). If you cna get composite sync directly from graphics card, then it is enough to just connect the H/HV connector to the composite sync pinput of the monitor.If you are on unfortunate person who deos not have this kind of graphics card or your drivers don't allow using that option, then your only choice is to build a circuit which combines the separate HSYNC and VSYNC signals to composite sync. You can see this kind of circuit below.
[h=3]Component list[/h]
