| 摘要 |
<p>The speed control device maintains the preset speed of a chart time scale constant. A test raster is applied on the chart, whose lines are perpendicular to the chart direction of movement. Spacing of the lines is in a rigid relation to the chart time scale. Raster lines are scanned by a sensor, and spacing of lines detected by the scanner is compared with a preset nominal value. In the case of a discrepancy, speed of the chart is readjusted. The drive motor revolutions can be continuously influenced by a stepped control arrangement using analogue actual values derived from impulse trains delivered from the sensor.</p> |
