| 摘要 |
<p>Case 2790 MONITOR FOR SCR SYSTEM A monitor for a system having a number of SCRs connected across an AC power source has several neon lamps connected across each SCR or each group of SCRs. The SCRs are at a high voltage and the neon lamp display is in proximity to the SCRs. The several neon lamps associated with one SCR or group of SCRs are formed in a cluster with the distance between clusters being greater than the distance between the lamps in a cluster. A video camera, spaced from the SCRs and substantially at ground potential provides an image of clusters of neon lamps. An image processor derives from the image, information on the location and light intensity of each cluster and this information is stored in a memory. In one form of the invention a lens over each cluster blurs the image of the cluster to make each cluster appears as a larger single light source rather than several individual light sources. If a cluster fails to light over a cycle of the AC power source, a decision processor provides an output indicating this. The decision processor can be programmed to shut down the system when a critical combination of SCRS fail. The condition of the lamps in each cluster is also monitored to determine lamp failure by comparing the light intensity from a cluster with a threshold that is stepped between a level representing no light and a level representing maximum light. A sudden decrease in the level of light from a cluster indicates lamp failure and a warning signal is provided.</p> |
