| 摘要 |
<p>Photosignal generator (LSG) contains LED, switch unit (S) for connecting LED to first (L1), or second phase (L2), and photodetector (LE) of light emitted by LED. Switch unit is controlled according to light emitted from LED and detected. Preferably LED is coupled to first phase when there is no impairing of function. Switch unit may disconnect LED from first phase and connect it to second phase, when detected light magnitude drops below first threshold value, and reconnects it to first phase, when detected light magnitude drops below second lower threshold. Independent claims are included for photosignal installation.</p> |
