Fairfild electrical components Germany Fairfild model Fairfild price

Fairfild electrical component is a photodetector that converts light into current or voltage signals depending on the mode of use. The die often uses a photosensitive PN junction, which is highly sensitive to changes in light, has unidirectional conductivity, and changes its electrical characteristics with different light intensities, allowing the current in the circuit to be changed by varying the light intensity. Photodiodes are also called photoelectric diodes. Photodiodes are similar in structure to semiconductor diodes; their die is a photosensitive PN junction with unidirectional conductivity, so a reverse voltage must be applied during operation. When there is no illumination, there is a very small saturated reverse leakage current, known as dark current, at which point the photodiode is cut off. When exposed to light, the saturated reverse leakage current increases significantly, forming a photocurrent that varies with the intensity of the incident light. When light irradiates the PN junction, it generates electron-hole pairs in the PN junction, increasing the density of minority carriers. These carriers drift under reverse voltage, causing the reverse current to increase. Therefore, the current in the circuit can be changed by varying the light intensity.

Fairfild electrical component applications

Basic circuits of analog integrated circuits include current sources, single-stage amplifiers, filters, feedback circuits, current mirror circuits, etc. Higher-level basic circuits composed of these include operational amplifiers and comparators, while even higher-level circuits include switched-capacitor circuits, phase-locked loops, and ADC/DAC. Based on the response relationship between output and input signals, analog integrated circuits can be divided into two major categories: linear integrated circuits and nonlinear integrated circuits. The response between the output and input signals of the former is usually linear; the shape of the output signal is similar to that of the input signal, only amplified by a fixed coefficient. In contrast, the output signal of nonlinear integrated circuits exhibits a nonlinear response to the input signal, such as square or logarithmic relationships, hence they are called nonlinear circuits. Common nonlinear circuits include oscillators, timers, and phase-locked loop circuits. Typical applications of analog integrated circuits are shown in the figure below: external natural signals collected by various sensors or antennas (such as temperature, humidity, optical, piezoelectric, and acoustic sensors) are preprocessed by analog circuits and converted into suitable digital signals for input into digital systems; signals processed by the digital system are then post-processed by analog circuits and converted into analog signals such as sound, images, and radio waves for output.

Fairfild electrical component classification

1, fuse resistors: also known as fusible resistors, they serve the dual function of a resistor and a fuse under normal conditions. When a circuit fault causes their power to exceed the rated power, they blow like a fuse to disconnect the circuit. Fuse resistors generally have low resistance values and low power ratings. 10, sensitive resistors: refer to resistors whose resistance values are sensitive to certain physical quantities (such as temperature, humidity, light, voltage, mechanical force, and gas concentration). When these physical quantities change, the resistance value of the sensitive resistor changes accordingly, presenting different resistance values. Based on sensitivity to different physical quantities, sensitive resistors can be classified into thermistors, humidity-sensitive resistors, photoresistors, varistors, force-sensitive resistors, magnetoresistors, and gas-sensitive resistors. The materials used for sensitive resistors are almost all semiconductor materials, so these resistors are also called semiconductor resistors. The resistance of a thermistor changes with temperature; those whose resistance decreases as temperature rises are negative temperature coefficient (NTC) thermistors. NTC thermistors are widely used and can be further divided into general-purpose NTC thermistors, voltage-stabilizing NTC thermistors, and temperature-measuring NTC thermistors. The resistance of a photoresistor changes with the intensity of incident light; when incident light increases, the resistance of the photoresistor decreases, and when incident light weakens, the resistance increases.

Fairfild electrical component functions

The main purposes of isolating switches (disconnectors) are: 1, to isolate the power supply, disconnecting high-voltage maintenance equipment from live equipment to provide a clearly visible break point. 2, to coordinate with circuit breakers for switching operations as required by system operating modes, thereby changing the system wiring configuration. 3, to connect or disconnect low-current circuits. Isolating switches can perform the following operations: breaking and making bypass currents of closed-loop switches; breaking and making grounding connections at transformer neutral points (however, if an arc-suppression coil is connected to the neutral point, operation is only permitted when the system is fault-free); breaking and making voltage transformers and surge arresters; breaking and making capacitive currents of busbars and equipment directly connected to busbars; breaking and making no-load lines with capacitive currents not exceeding 5 amperes; three-gang isolating switches can break and make loads with voltages up to 10 kilovolts and currents below 15 amperes. When operating isolating switches, note that when energizing a line, close the busbar-side isolating switch first, then the line-side isolating switch, and finally the circuit breaker. When de-energizing a line, open the circuit breaker first, then open the isolating switches. Do not operate high-voltage isolating switches under load.

Weidou Intelligent Technology professionally sells German Fairfild connectors, Fairfild switches, Fairfild relays, Fairfild controllers, Fairfild plugs, Fairfild sensors, Fairfild resistors, Fairfild capacitors, Fairfild buses, Fairfild modules, Fairfild cables, Fairfild power supplies, Fairfild interfaces, Fairfild gateways, Fairfild circuit breakers, Fairfild original imports from Germany. Welcome customers to inquire and order.