Abstract: A binary frequency divider circuit with insulated gate field effect transistors (MOST) powered by a constant voltage source is derived from a known static circuit by eliminating transistors that do not take part in switching, which allows nodes of the circuit to float. Certain transistors, which are eliminated in known dynamic circuits, are retained so that the nodes float for only one value of an input variable, but not for the other.

Abstract: A device for providing an electro-optical display of time comprises an electronic timekeeper fed by a voltage source and including a time base and a frequency divider. An electro-optical display is formed of groups of electro-chromic cells each able to take two different visual aspects. The cells are controlled by a code converter supplying state variables corresponding to the desired aspects of the cells to provide a display of time. One aspect of the cells corresponds to a stable state, the other aspect to a quasi-stable state which in order to be maintained, requires very low or zero power. Transition of a cell from one state to another requires precisely determined amounts of energy. A change detector supplies to a selector, data to actuate the operations of inscription and erasure of the display cells.