ELM - NTSC(YC/RGB) to VGA Scan Converter

[wellington]

From: ELM

This is a video scan converter to display NTSC video signal into VGA monitor. Normally, the VGA monitor occupies most desk top space, so that everybody will be thinking that if the VGA monitor can be used for video monitor.

I tried to build a scan converter. Right photo shows my VGA monitor which displays TV. The VGA monitor (Nanao T560iJ) has two VGA inputs, BNCs and a D-sub, it can easy to change its inputs without any external video swicher. A small monitor at left end of the photo is a sub-monitor to be used during the VGA monitor is used for PC.

Now, difference between NTSC and VGA is shown in table 1. The horizontal refresh rate for VGA is just two times faster than NTSC, and vertical refresh rates are equal. Thus, only converting the horizontal refresh rate is sufficient for NTSC to VGA scan converter and its circuit diagram is very simple. If there is difference between vertical refresh rates such as PAL to VGA converter, it will require frame buffer, the circuit diagram will become complexity.