Duty cycle in the context of Unipolar encoding

A square wave is a non-sinusoidal periodic waveform in which the amplitude alternates at a steady frequency between fixed minimum and maximum values, with the same duration at minimum and maximum. In an ideal square wave, the transitions between minimum and maximum are instantaneous.

The square wave is a special case of a pulse wave which allows arbitrary durations at minimum and maximum amplitudes. The ratio of the high period to the total period of a pulse wave is called the duty cycle. A true square wave has a 50% duty cycle (equal high and low periods).

Horseshoe bats are bats in the family Rhinolophidae. In addition to the single living genus, Rhinolophus, which has about 106 species, the extinct genus Palaeonycteris has been recognized. Horseshoe bats are closely related to the Old World leaf-nosed bats, family Hipposideridae, which have sometimes been included in Rhinolophidae. The horseshoe bats are divided into six subgenera and many species groups. The most recent common ancestor of all horseshoe bats lived 34–40 million years ago, though it is unclear where the geographic roots of the family are, and attempts to determine its biogeography have been indecisive. Their taxonomy is complex, as genetic evidence shows the likely existence of many cryptic species, as well as species recognized as distinct that may have little genetic divergence from previously recognized taxa. They are found in the Old World, mostly in tropical or subtropical areas, including Africa, Asia, Europe, and Oceania.

Horseshoe bats are considered small or medium-sized microbats, weighing 4–28 g (0.14–0.99 oz), with forearm lengths of 30–75 mm (1.2–3.0 in) and combined lengths of head and body of 35–110 mm (1.4–4.3 in). The fur, long and smooth in most species, can be reddish-brown, blackish, or bright orange-red. They get their common name from their large nose-leafs, which are shaped like horseshoes. The nose-leafs aid in echolocation; horseshoe bats have highly sophisticated echolocation, using constant frequency calls at high-duty cycles to detect prey in areas of high environmental clutters. They hunt insects and spiders, swooping down on prey from a perch, or gleaning from foliage. Little is known about their mating systems, but at least one species is monogamous, while another is polygynous. Gestation is approximately seven weeks and one offspring is produced at a time. A typical lifespan is six or seven years, but one greater horseshoe bat lived more than thirty years.

In electronics and especially synchronous digital circuits, a clock signal (historically also known as logic beat) is an electronic logic signal (voltage or current) which oscillates between a high and a low state at a constant frequency and is used like a metronome to synchronize actions of digital circuits. In a synchronous logic circuit, the most common type of digital circuit, the clock signal is applied to all storage devices, flip-flops and latches, and causes them all to change state simultaneously, preventing race conditions.

A clock signal is produced by an electronic oscillator called a clock generator. The most common clock signal is in the form of a square wave with a 50% duty cycle. Circuits using the clock signal for synchronization may become active at either the rising edge, falling edge, or, in the case of double data rate, both in the rising and in the falling edges of the clock cycle.

A switched-mode power supply (SMPS), also called switching-mode power supply, switch-mode power supply, switched power supply, or simply switcher, is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently.

Like other power supplies, a SMPS transfers power from a DC or AC source (often mains power, see AC adapter) to DC loads, such as a personal computer, while converting voltage and current characteristics. Unlike a linear power supply, the pass transistor of a switching-mode supply continually switches between low-dissipation, full-on and full-off states, and spends very little time in the high-dissipation transitions, which minimizes wasted energy. Voltage regulation is achieved by varying the ratio of on-to-off time (also known as duty cycle). In contrast, a linear power supply regulates the output voltage by continually dissipating power in the pass transistor. The switched-mode power supply's higher electrical efficiency is an important advantage.