[[Image:RGBtoSVideoPCBMini_S_Video3.jpg|300px400px|right]][[Image:RGBtoSVideoComponent.jpg|300px|right]][[Image:AD724.JPG|300px|right]]
== Description ==
The AD724 is a complete RGB to S-Video / composite converter in a single ICconfigurable for both PAL and NTSC formats but not SECAM. It requires just a few external components to complete the system. It is only available in an SMD package. You can choose to make the entire PCB in SMD or use a mixture of SMD and standard parts for the external components. Unlike the MC1377 used in older Modulators, the AD724 requires just 5V, meaning it is ideally suited for installation in the CPC Plus range and Classic 464, both of which don't have an internal 12V source (required by the MC1377).The IC can be configured for several different input and output systems. The main configurations needed for the CPC with PAL output are as follows:
The composite output of the AD724 produces a 2.5V peak to peak signal for both PAL and NTSC. The S-Video Chrominance output is approximately 1.8V peak to peak and the Luminance is around 2V peak to peak. These values are all within the Composite / S-video standards and should be compatible with all TVs, Displays and further converters.
S-Video and composite signals contain only picture information, they do not contain any sound information, so don't expect the CPCs sound to come out of the TV.
In the miniature layout seen below a bypass diode (1N4001) was also added to the supply input. This diode protects the IC in case the user wrongly connects the power the circuit, which would otherwise result in the AD724 being fried. This diode isn't currently shown in the schematics, nor is it included in the large S-Video plus composite layout below. (Schematics and large layout , but will be modified added soon).
* If your modulator only has the S-Video ouput, you can still connect to a composite TV input by using an S-Video to composite adapter. This adapter combines the Chrominance and Luminance signals back together (passively), but again the quality will not be as good as the S-Video picture, so this method should only be considered as a last resort.
== Internal Installation ==
If you do decide to install the miniature version of the modulator inside a CPC or even just give it a casing, the following dimensions can be used. The 42mm x 27mm dimensions of the PCB may vary slightly.
[[Image:AD724_Dim.png|480px|centre]]
The new mini version is a mere 32mm x 25mm and is even easier to fit inside most computers.
[[Image:Mini_S_Video2.jpg|480px|centre]]
The following files are the PCB and component position layouts to construct the circuit above:
[[File:AD724_Mod_Layout.pdf]] - PCB Track Layout for full SMD version (with Composite Output) as seen in the third picture above. The miniature S-Video only layout with mixed SMD / through-pin components will be uploaded soon.
[[File:AD724_Mini_Layout.pdf]] - Miniature PCB Track Layout with mixed SMD / through-pin components (only has S-Video Socket).
== NTSC ==