Simple Sump Pump Controller

After one too many flooded basements, the author of this design was fed up. The mechanical float switch for the sump pump, which pumps the water from the washing machine up to the sewer level, was increasingly often jammed by caked-on detergent. It seemed like a good idea to replace this switch by an electronic version with two sensors. In order to avoid unnecessary effort, an existing Elektor Electronics circuit wastaken as a model, namely the ‘simple moisture detector’ in the December 1998 issue.