| 摘要 |
The photocells are optically directed towards a point, pref. at an infinite distance from them, for monitoring radiation e.g. daylight. They feed a signal processing circuit contg. a neutral passage amplifier, a signal forming stage, and a control circuit for an output signal stage. In their electrical counter-parallel coupling, the pair of photocells have one common conductor connected to an input of an operation amplifier, the other input of which is connected to their other common conductor. The amplifier output is connected to the signal processing circuit, and is also back-coupled to one of the amplifier inputs. The signal processing circuit neutral through passage amplifier, signal forming stage and control circuit each comprise exclusive-or grids. The thiro grid has its output connected to the grid of a field effect transistor comprising the output signal stage, and dependent upon output signals from this grid is passive or active for activation of an indicator. |
