Abstract: Methods, systems and computer readable code for controlling a defrost cycle of a refrigeration device are disclosed. According to some embodiments, a defrost command is issued to a defrost heater at a time determined at least in part by a total wasted energy parameter of the compressor for at least one time interval. In some embodiments, time interval includes a plurality of runtimes, and the total wasted energy parameter of a runtime is measured relative to a chosen reference runtime such as a minimum energy runtime after a defrost or an early runtime after a defrost. Optionally, a sequence of wasted energy parameters of the compressor for a sequence of time intervals is analyzed, and then a correction is performed on at least one wasted energy parameter.

Abstract: Apparatus and methods for indicating speed deviations of a motor vehicle are disclosed herein. In some embodiments, upon a user engagement of a user input interface (for example, a button or dial or any other input device), a reference speed of the motor vehicle is desired. Indications of subsequent speed deviations from the reference speed are provided, for example, in a non-numerical or non-textual visual signal having a luminous intensity of at least 2000 minicandles, in a driver cone of sight defined by the motor vehicle. In some embodiments, the visual signal indicates which of three ranges of speed the driver is driving in, including too fast, too slow and a mid range.