| 摘要 |
<p>A microprocessor controlled time switch has a liquid crystal display device (13) with provision for displaying day of the week and time. Below the display a row of four keys (21 to 24) are used to select programming functions and a key (20) can be pressed at either end to increment and decrement numerical values. The keys (21 to 24) are multi-function and, above each key, the display device (13) includes a column of three legends, of which only one is ever displayed at a time. The microprocessor controls the legends (27) so that, in all phases of operation, the functions performed by the keys (21 to 24) are apparent.</p> |
