Those who own a significant amount of audio and video equipment are faced with a choice: make it yourself or purchase an adapter from the store that will convert signals of different types. Needless to say, factory devices cost a lot, but you can often do without them. And within the article we will talk about how to make a VGA to RCA adapter. Frequently asked questions will also be answered.
What is a VGA RCA adapter
The circuit of this device may seem complicated, but only until you understand it. What is this device? This is an adapter from tulips (RCA connectors) of analog video output to VGA D-Sub for 15 pins. The device reviewed here can be used to connect a DVD player or satellite tuner to a multimedia projector. Of course, provided that it is not possible to work directly using the same type of cable, which is usually common in cheap or outdated devices.
SCART connector
SCART connector (“Syndicat Français des Constructeurs d'Appareils Connector Radio et Télévision” from French “Association of the Radio and Television Industry”). An analog signal connector, SCART is a physical and electrical connection between two pieces of audiovisual equipment, such as televisions and VCRs, DVD players, and audio equipment. SCART was designed to eliminate confusion with wires and connectors. Developed by Peritel in France and also known as the "EURO connector", the SCART cable uses 21-pin male connectors at both ends. Today, most new televisions and VCRs in the European market and other countries that use the PAL video standard are equipped with a SCART connector.
Bidirectional
Composite video and analog lines are bi-directional, allowing pay TV and teletext to be sent from the TV to the set-top box for decoding and then back to the TV.
What is the idea?
How to implement such an idea? You need a computer cable (twisted pair type CAT5/CAT5e) designed to transmit video signals. We will use it because the transmission is carried out over a distance of fifty meters without loss of quality.
First, we need to acquire three RCA connectors and one D-Sub15 pin (this is a plug), as well as a twisted pair cable. The last part is better to use shielded STP than UTP. But this one is more difficult to get, which affects the price. Therefore, the issue of possibilities and desires is considered here. There is no particular difference between the elements, but there is one nuance: it is better to use UTP if the cable length is less than 10 meters. If the distance is greater, then it would still be better to find STP.
Connectors
Most models of TV set-top boxes have a large number of connectors and interfaces. Of course, it would be easier to equip the device with one universal output for convenience, but not every home has a TV, for example, with a modern HDMI interface. Yes, such an output is capable of transmitting video and audio signals as correctly as possible, but such models are not cheap and not everyone can afford them.
Some people still can’t part with their “ancient” TVs, so many TV set-top boxes are burdened with versatility for the sake of convenience. However, before purchasing a set-top box, it would not be superfluous to check whether it has one or another connector/interface for your TV. Also keep this in mind before connecting your TV to the receiver.
Pinout
How to pinout a 15 pin D-Sub connector? The numbers go from left to right:
1 – RY (Pr). 2 – Y. 3 – BY (Pb). 4 – Ground – Brown. 5 – Ground – Wht\Brown. 6 – Ground RY (Pr) – Wht\Red. 7 – Ground Y – Wht\Green. 8 – Ground BY (Pb) – Wht\Blue. 9 – Not needed. 10 – Ground. 11 – Not needed. 12 – DDC DAT. 13 – Horizontal Synchronization. 14 – Vertical Synchronization. 15 – DDC Clock.
For the VGA RCA adapter cable we need six pins out of the fifteen presented. How to properly wire connectors and contacts? Check out this picture and you will understand how and what to do.
So let's see what happened. If everything was soldered correctly, then you now have an adapter that can supply a video signal to VGA D-Sub on the 15 pins of the projector. You can see approximately what the final product should look like in the photographs presented in the article.
Those annoying 20 contacts and ground
As a rule, the connecting cord was a cable, on one side of which there was a SCART connector, on the other, two, four or six contact groups of the American standard RCA (called “tulips” for their specific shape). At its core, it was a simple adapter that allowed for galvanic connection of the source with a video monitor (TV). Owners of video equipment often cursed, cursing the imperialists for the lack of desire for universal standardization, believing that 21 contacts for such a simple device was too many.
Only television specialists, for whom the SCART connector diagram did not constitute a “Chinese letter”, were able to appreciate the full potential of this approach on the part of the French Union of Electronics Manufacturers, in honor of which it received its name (Syndicat Des Constructeurs D'Appareils, Radiorecepteurs Et Televiseurs - SCART).
(1 rating, average 5 out of 5)
Examination
Wire pairs with RCA plugs soldered at the ends can be usefully compressed with heat shrink to obtain greater rigidity. In general, now you can connect the result of your work and enjoy it (if everything was soldered together as needed). Paired wires, at the ends of which RCA plugs are attached, can be crimped with heat shrink to obtain greater rigidity.
In this case, we used a satellite tuner with a 3 RCA component video output as a signal source and a Sanyo multimedia projector, which did not have a separate video input of the same type. If at the moment it is not possible to verify the functionality of the resulting adapter, then you can only carefully inspect the entire structure and make sure that there were no omissions, and everything is soldered as indicated in the article.
SCART pinout
The abbreviation SCART (Syndicat des constructeurs d”appareils radio recepteurs et televiseurs) is translated from French as “Association of the Radio and Television Industry”. The European unified connector, developed at the very beginning of the eighties, was intended for connecting various devices: a TV with a printer in the Videotext system, a keyboard in the Teletext system, VCRs, video players and Hi-Fi devices, a home computer, etc. The SCART connector is used not only in all European-made devices, but also in most Japanese devices.
What you need to understand
You should be aware that the adapter in question can ensure the operation and full functioning of a device that has a VGA video input only if it can automatically detect the type of incoming video signal. An indicator of this will be the ability to select the mode in which data will be transmitted to RGB/YPbPr. Usage will be positively impacted by sending these types of signals. Why is that?
The fact is that RGB and HV.sync (for example, data coming from the output of a personal computer’s video card) are converted to RGB, which has sync pulses in the green channel (Y). It, in turn, turns into the color-difference YPbPr. And as a result, we can conclude that these signals are not the same thing, although they can convey the same information. Therefore, carefully study what a VGA RCA adapter looks like.
How to connect video to domestic TVs
The lucky owners of the Japanese or South Korean miracle soon came to the conclusion that our televisions could well be used to watch foreign video programs. Most Soviet devices, modern at that time, already had all the necessary devices for connecting video equipment, namely: a built-in PAL-SEKAM decoder and a SCART connector on the back cover. They were also equipped with remote control or had the ability to easily install the necessary boards, control modules and infrared signal photodetectors. A shortage immediately arose for the appropriate connecting cables, which was readily filled by numerous cooperatives and private enterprises.
What adapters can be made using twisted pair?
- VGA extenders are special cables that have D-Sub 15 pin connectors on both ends, while their input and output use the same technology.
- RCA (3xRCA) is used to transmit component video signals. There are three connectors at each end. Used when working with a DVD player and TV.
- RCA (D-Sub15pin) was discussed a little higher. Here are the components Y, Pr, Pb in VGA.
- To transmit analog audio, two pairs of stereo signals can be used simultaneously (4 RCA connectors at each end).
Design
Many people who want to make a SCART-tulip adapter with their own hands try to understand the design of this interface.
First of all, it is worth noting that there are 20 pin contacts in this connector, and the role of the 21st contact is assigned to a specialized metal screen, which is located along the entire perimeter of this connector. Its second purpose is to protect the contacts from any mechanical influences from the outside, and the mating part is made using plastic injection. It is worth noting that it can have not only lugs for self-tapping screws and screws, but also bosses intended for installation on printed circuit boards.
The design of cable connectors of this type can hardly be called original, however, there are three main types that differ from each other in the design of the housing - the cable can be routed straight, at an angle or to the side. The connector is held in the socket by specialized spring-loaded male contacts, thanks to which even the SCART-USB adapter is famous for its incredible reliability and fastener strength
Even such cables have to be inserted quite carefully so as not to move the device.
Why is it so difficult? But why!
Unlike conventional “tulips”, the SCART RCA connector has a number of advantages that provide extensive control capabilities, better color reproduction and even digital broadcasting, unthinkable in the early 80s (it was developed in 1983).
Today, even consumers who are little educated in electronics know that the variety of colors on the screen is created by only three components: red, green and blue. Their separate supply to the color module eliminates a number of interferences and makes the picture clearer. This opportunity is provided by the SCART connector, in which the 7th, 11th and 15th pins are designed to supply an RGB signal, and the 5th, 9th and 13th, alternating with them, are intended for shielding shells.
But this is not all the capabilities that the SCART connector has. The pinout assumes the ability to automatically turn on and off the TV simultaneously with a low-frequency signal source (DVD or VCR), regardless of which company manufactured the equipment. The widescreen display mode also turns on independently.
In addition to these functions, there are two digital contacts - the 12th and 14th, prophetically identified by French engineers back in 1983, when almost all consumer electronics were analog. There is also a connector for connecting a timer, it is number ten.
So, 20 contacts and one common one (21 in total) - this turns out to be not so much. For modern entertainment video centers they are still sufficient, although they are no longer enough to enable Dolby Surround...
Article rating:
What is a scart connector on a TV Link to main publication
Related publications
How to properly connect current transformers to the meter
conclusions
Despite the assurances of sellers, such converters should not be used. The probability of correct connection and data transfer in this case does not exceed a few percent - and, according to some experts, is generally zero. It will be much more effective to purchase a converter that is guaranteed to perform its functions by connecting a digital video card to an analog output device.
Bogdan Vyazovsky
“We live in a society where technology is a very important part of business, our daily lives. And all technology starts with sparks in someone's head. The idea of something that didn't exist before but will one day be invented can change everything. And this activity is generally not very well supported."
