PWM (abbreviation for pulse width modulation) is a type of digital modulation in which a technical variable (e.g. an electrical voltage) alternates between two values. A rectangular pulse is generated (modulated) at a constant frequency, the width and length of which varies. The ratio between pulse and period duration (sum of pulse and pause duration) […]
The QR code (Quick Response Code; 2D code) was developed at Denso (Japan) in 1994. It is square and easy to recognize thanks to its search aids, light and dark squares nested in each other in three corners. The symbol elements are squares, of which there are at least 21 x 21 and a maximum […]
Quality assurance (QA) or quality control (QC) are umbrella terms for many different methods, procedures and measures for achieving and ensuring defined quality requirements. According to DIN EN ISO 9000:2015, quality assurance is the area of quality management that aims to create confidence in the quality of products. In Germany, quality assurance has become increasingly […]
REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) Regulation (EC) No. 1907/2006 is a chemicals regulation of the European Union that came into force on June 1, 2007. REACH deals with the manufacture and use of chemical substances and their possible effects on human health and the environment. See also RoHS.
Reed-Solomon error correction, an error correction method for sending and receiving digital data(2D codes), was originally developed for NASA. It was used in space probes for radio data transmission, where the outgoing signal weakens considerably over time and becomes increasingly noisy. Reed and Solomon were two mathematicians at Hughes Aerospace who developed this mathematical procedure […]
Ring-shaped illuminators provide intense, shadow-free light that falls along the optical axis of the camera. They are often used in conjunction with polarizing filters, which eliminate interfering reflections. Ring lights are available in various designs. At Büchner you will find a large selection of ring lighting → here.
RoHS is an EU directive that was passed in 2011 and prohibits or restricts the use of certain hazardous substances in the electronics sector. The abbreviation stands for “Restriction of Hazardous Substances”. To avoid environmental hazards and pollution from hazardous substances, all products on the EU market must be RoHS compliant. (The abbreviation was originally […]
– Term used in many technical and scientific disciplines for the adaptation of representations, objects and constructions to changed scales; – Mathematicians understand this to mean the change in a value depicted on a scale; – Graphic designers, on the other hand, change the size of an image.
SELV (Safety Extra Low Voltage) describes a voltage that is set so low that there is no danger from excessive body currents when touching it directly, either during normal operation or in the event of a single fault. If insulation fails, there must still be sufficient protection. In the case of power supply units, this […]
