16-450: Konami Kukeiha Club ( コナミ矩形波倶楽部 , konami kukeiha kurabu , lit. "Konami Square Wave Club", referring to square waves used in chiptunes in the 1980s) is Konami 's sound team. It is often confused with 矩形波倶楽部 ( Kukeiha Club ), Konami's in-house band that has released albums consisting of their studio performances. They are primarily responsible for the sound and music in the majority of Konami video games. One of their best known works
32-399: A circuit or cause a badly positioned threshold to be crossed multiple times.) As already mentioned, an ideal square wave has instantaneous transitions between the high and low levels. In practice, this is never achieved because of physical limitations of the system that generates the waveform. The times taken for the signal to rise from the low level to the high level and back again are called
48-447: A video game musician is a stub . You can help Misplaced Pages by expanding it . This article about a Japanese band or other musical ensemble is a stub . You can help Misplaced Pages by expanding it . Square wave 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,
64-422: A wide range of harmonics; these can generate electromagnetic radiation or pulses of current that interfere with other nearby circuits, causing noise or errors. To avoid this problem in very sensitive circuits such as precision analog-to-digital converters , sine waves are used instead of square waves as timing references. In musical terms, they are often described as sounding hollow, and are therefore used as
80-413: Is a two-state trajectory . Square waves are universally encountered in digital switching circuits and are naturally generated by binary (two-level) logic devices. They are used as timing references or " clock signals ", because their fast transitions are suitable for triggering synchronous logic circuits at precisely determined intervals. However, as the frequency-domain graph shows, square waves contain
96-603: Is the soundtrack to Gensō Suikoden — the majority of the material being composed by member Miki Higashino (Miki-Chan). Motoaki Furukawa (main arranger and guitarist) has been known to perform live with members not part of the in-house band, credited under "Konami Kukeiha Club". For example, disc 1 of the Konami All Stars: The Senryo-Bako Heisei 4 Nen Ban album (KICA-1053~55) is titled "Konami Kukeiha Club Live in Tōkyō." This article about
112-417: The rise time and the fall time respectively. If the system is overdamped , then the waveform may never actually reach the theoretical high and low levels, and if the system is underdamped, it will oscillate about the high and low levels before settling down. In these cases, the rise and fall times are measured between specified intermediate levels, such as 5% and 95%, or 10% and 90%. The bandwidth of
128-503: The floor function directly: x ( t ) = 2 ( 2 ⌊ f t ⌋ − ⌊ 2 f t ⌋ ) + 1 {\displaystyle x(t)=2\left(2\lfloor ft\rfloor -\lfloor 2ft\rfloor \right)+1} and indirectly: x ( t ) = ( − 1 ) ⌊ 2 f t ⌋ . {\displaystyle x(t)=\left(-1\right)^{\lfloor 2ft\rfloor }.} Using
144-512: The basis for wind instrument sounds created using subtractive synthesis . They also make up the "beeping" alerts used in many household, commercial, and industrial contexts. Additionally, the distortion effect used on electric guitars clips the outermost regions of the waveform, causing it to increasingly resemble a square wave as more distortion is applied. Simple two-level Rademacher functions are square waves. The square wave in mathematics has many definitions, which are equivalent except at
160-837: The discontinuities: It can be defined as simply the sign function of a sinusoid: x ( t ) = sgn ( sin 2 π t T ) = sgn ( sin 2 π f t ) v ( t ) = sgn ( cos 2 π t T ) = sgn ( cos 2 π f t ) , {\displaystyle {\begin{aligned}x(t)&=\operatorname {sgn} \left(\sin {\frac {2\pi t}{T}}\right)=\operatorname {sgn}(\sin 2\pi ft)\\v(t)&=\operatorname {sgn} \left(\cos {\frac {2\pi t}{T}}\right)=\operatorname {sgn}(\cos 2\pi ft),\end{aligned}}} which will be 1 when
176-605: The form 2π(2 k − 1) f ). A curiosity of the convergence of the Fourier series representation of the square wave is the Gibbs phenomenon . Ringing artifacts in non-ideal square waves can be shown to be related to this phenomenon. The Gibbs phenomenon can be prevented by the use of σ-approximation , which uses the Lanczos sigma factors to help the sequence converge more smoothly. An ideal mathematical square wave changes between
SECTION 10
#1732791542382192-1795: The fourier series (below) one can show that the floor function may be written in trigonometric form 2 π arctan ( tan ( π f t 2 ) ) + 2 π arctan ( cot ( π f t 2 ) ) {\displaystyle {\frac {2}{\pi }}\arctan \left(\tan \left({\frac {\pi ft}{2}}\right)\right)+{\frac {2}{\pi }}\arctan \left(\cot \left({\frac {\pi ft}{2}}\right)\right)} Using Fourier expansion with cycle frequency f over time t , an ideal square wave with an amplitude of 1 can be represented as an infinite sum of sinusoidal waves: x ( t ) = 4 π ∑ k = 1 ∞ sin ( 2 π ( 2 k − 1 ) f t ) 2 k − 1 = 4 π ( sin ( ω t ) + 1 3 sin ( 3 ω t ) + 1 5 sin ( 5 ω t ) + … ) , where ω = 2 π f . {\displaystyle {\begin{aligned}x(t)&={\frac {4}{\pi }}\sum _{k=1}^{\infty }{\frac {\sin \left(2\pi (2k-1)ft\right)}{2k-1}}\\&={\frac {4}{\pi }}\left(\sin(\omega t)+{\frac {1}{3}}\sin(3\omega t)+{\frac {1}{5}}\sin(5\omega t)+\ldots \right),&{\text{where }}\omega =2\pi f.\end{aligned}}} The ideal square wave contains only components of odd-integer harmonic frequencies (of
208-459: The high and the low state instantaneously, and without under- or over-shooting. This is impossible to achieve in physical systems, as it would require infinite bandwidth . Square waves in physical systems have only finite bandwidth and often exhibit ringing effects similar to those of the Gibbs phenomenon or ripple effects similar to those of the σ-approximation. For a reasonable approximation to
224-1324: The sinusoid is positive, −1 when the sinusoid is negative, and 0 at the discontinuities. Here, T is the period of the square wave and f is its frequency, which are related by the equation f = 1/ T . A square wave can also be defined with respect to the Heaviside step function u ( t ) or the rectangular function Π( t ): x ( t ) = 2 [ ∑ n = − ∞ ∞ Π ( 2 ( t − n T ) T − 1 2 ) ] − 1 = 2 ∑ n = − ∞ ∞ [ u ( t T − n ) − u ( t T − n − 1 2 ) ] − 1. {\displaystyle {\begin{aligned}x(t)&=2\left[\sum _{n=-\infty }^{\infty }\Pi \left({\frac {2(t-nT)}{T}}-{\frac {1}{2}}\right)\right]-1\\&=2\sum _{n=-\infty }^{\infty }\left[u\left({\frac {t}{T}}-n\right)-u\left({\frac {t}{T}}-n-{\frac {1}{2}}\right)\right]-1.\end{aligned}}} A square wave can also be generated using
240-405: The square-wave shape, at least the fundamental and third harmonic need to be present, with the fifth harmonic being desirable. These bandwidth requirements are important in digital electronics, where finite-bandwidth analog approximations to square-wave-like waveforms are used. (The ringing transients are an important electronic consideration here, as they may go beyond the electrical rating limits of
256-524: 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). Square waves are often encountered in electronics and signal processing , particularly digital electronics and digital signal processing . Its stochastic counterpart
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