| 摘要 |
A voltage sensitive device controls the energization of a relay or other load so as to switch it between energized and de-energized states as the sensed voltage passes a low or undervoltage limit and another high or overvoltage limit. Detection of the high and low limits is achieved by two voltage detecting circuits, one for each limit, and a comparator circuit responsive to the outputs of the detecting circuits performs the actual switching of the load between its energized and de-energized states. The two detecting circuits and the comparator circuit are each comprised principally of a programmable unijunction transistor or other three-terminal semiconductor device of generally similar characteristics.
|
