Modular electronic timer switch system

Abstract

Each of several, typically three, microprocessorcontrolled modular electronic timers is selectably electrically pluggable to each of several, typically four, custom packaged modular switches. Each modular switch contains an indentical switch circuit that selectively implements the SPST through 4PST, the DPDT, or the DPST switch function. Each modular timer variously provides eight on/off events, either upon five weekdays and upon two weekend days, or upon individual days. Each modular timer may skip timed events during a one to seven day period. An astronomical timer generates an on/off signal at local sunrise and sunset without reference to ambient light conditions. Each timer is readily programmed, and toggled in its on/off signal state, by pushbutton switches. A comprehensive display shows current programmed data and on/off signal status. Each modular switch typically has two pairs of relays that are oppositely controlled. Solely by external electrical connections to the terminals of these relays, and by a further internal jumper particularly in order to realize the 3PST and 4PST switching functions, the same switch circuit is used in all four custom packagings. The custom packagings of the modular switch provide for easy installation while the common switch circuit accords reliable performance of diverse switching functions.