Analyses of a 238-year long monthly precipitation time sequence by use of filtering techniques

Improved redundant relay control circuits are set forth which prevent a load from being energized when any relay coil or contact or stop or start switch contact fails. A first circuit embodiment sets forth a plurality of branches with a cross-monitoring interconnection between a start branch and one of the two other circuit branches. The interconnection prevents a load from being energized when a start switch welds. Second and third circuit embodiments are configured such that the redundant control relay circuit remains inoperative until a fault is cleared although the main power across the circuit is temporarily removed. A fourth circuit embodiment operates independent of relay contact timing.