US Patent 10990115 Chemical controller system and method

A chemical controller for an aquatic application comprising an output relay. The chemical controller further includes a current detection circuit configured to detect current on an output of the output relay and a current fault detection device configured to output a current fault signal when a current fault condition has occurred. A relay latch of the chemical controller receives the relay enable signal and the current fault signal and decouples the relay enable signal from a corresponding output when a current fault condition has occurred. A relay drive circuit receives a signal from the corresponding output to responsively activate and deactivate the output relay. A watchdog timer circuit causes the output relay to be deactivated in response to detecting a hung processor.