Color display maintenance signal source made with integrated circuit MSE681N

The color display maintenance signal source made with the integrated circuit MSE681N can meet the needs of offline maintenance of color display and eliminate the inconvenience caused by connecting to the host each time. The output signal types of the signal source are shown in the table below, and the circuit is shown in the figure below.

1. Principle Introduction

The core device is MSE681N, which contains the central processor, image formation and synchronization generation, synchronization formation, RGB synthesis and synchronization pulse polarity control and other functional units. The circuit of the entire signal source is relatively simple, S1~S6 are six signal selection keys for signal conversion; TX1, C1, C2 are the clock oscillation elements of the central processor inside the IC; the primary color data signal is input from the emitter of Vl~V3; CKI and CK2 are standard D-type 15-pin and 9: signal input terminals, respectively, for connecting with various types of color displays.

2. Component Selection and Production

The signal selection keys S1~S6 can be replaced by a special circuit board with a keyboard or a micro switch for a TV; CKI and CK2 are available in computer accessory stores; the resistors are all 1/8W ordinary resistors, and other components are marked as shown in Figure 1. This circuit is easy to make and can work without debugging as long as the connections are correct.

3. Instructions

After the circuit is installed: connect the signal source and the color display power supply, and you can display the 640x48OA mode image (standard color bar). At this time, the horizontal and vertical synchronization are all negative polarity, which is suitable for most popular color displays. If the display is abnormal, press the S2/S3 button to select horizontal and vertical synchronization signals of different polarities.

The signal keyboard controls are as follows: S1 is standard color output; S2, S3; polarity selection of field synchronization signal; S4, S5 are respectively for selecting the resolution of 800x600 and 1024x768; S6 selects the white field, which is used to adjust the color display's film balance.

Serial number resolution synchronous polarity image 1 640x480A HV- white yellow cyan green purple red blue black 2 640x480B H+V- (judged from top to bottom) red, green, blue 3 640x480C H-V+ color blocks and color bars 4 800x600 HV- color blocks and color bars 5 1024x768 HV- color blocks and color bars 6 460x480 Hv- white field