| 摘要 |
The appts. has a number of light emitters and opto-electronic receivers. The latter receive transmitted light beams, and dependent upon the alterations in the amount of received light, they alter their electrical voltage condition between different levels. A detector unit comprises a first component which initiates transmission of a signal when the voltage condition surpasses a predetermined level, with a second component causing an output signal to be transmitted when a specific speed of variation in voltage is exceeded. The opto-electronic receivers are coupled in parallel with derivate circuits connected to each of them. These circuits are also connected to a threshold detector input with adjustable level for sensitivity control. (Provisional Basic Advised week K09) |
