fli electrical components German fli models fli prices

fli electrical components are electronic devices made from semiconductor materials (such as silicon, selenium, and germanium). A diode has two electrodes: the positive electrode, also called the anode, and the negative electrode, also called the cathode. When a forward voltage is applied across the two terminals of the diode, it conducts; when a reverse voltage is applied, it blocks. The conduction and blocking of the diode are equivalent to the closing and opening of a switch. Diodes have unidirectional conductivity; during conduction, current flows from the anode through the device to the cathode. As one of the earliest semiconductor devices, diodes are widely used. Especially in various electronic circuits, by reasonably connecting diodes with resistors, capacitors, inductors, and other components to form circuits with different functions, operations such as AC rectification, demodulation of modulated signals, limiting and clamping, and power supply voltage stabilization can be achieved.

fli electrical component structure

The structure and materials of new high-voltage Schottky diodes differ from those of traditional Schottky diodes. Traditional Schottky diodes are formed by metal-semiconductor contact. Metals such as aluminum, gold, molybdenum, nickel, and titanium can be used, while the semiconductor is typically silicon or gallium arsenide. Since electrons have higher mobility than holes, N-type semiconductor material is selected as the substrate to achieve good frequency characteristics. To reduce the junction capacitance of the Schottky diode and increase the reverse breakdown voltage without causing excessive series resistance, a high-resistance N- thin layer is usually epitaxially grown on an N+ substrate. It is well known that metal conductors contain a large number of conduction electrons. When metal contacts a semiconductor (with a separation distance on the order of atomic size), the Fermi level of the metal is lower than that of the semiconductor. In the metal and at the energy levels corresponding to the semiconductor conduction band, the electron density is lower than that in the semiconductor conduction band. Therefore, after contact, electrons diffuse from the semiconductor to the metal, causing the metal to become negatively charged and the semiconductor positively charged. Since metal is an ideal conductor, the negative charge is distributed only within a surface layer of atomic thickness. For N-type semiconductors, the donor impurity atoms that lose electrons become positive ions and are distributed over a larger thickness. The result of electron diffusion from the semiconductor to the metal forms a space charge region, a built-in electric field, and a potential barrier, with the depletion layer located only on the N-type semiconductor side (the entire barrier region falls on the semiconductor side). The direction of the built-in electric field in the barrier region points from the N-type region toward the metal. As thermionic emission increases the built-in field, the drift current, which opposes the diffusion current, increases until dynamic equilibrium is reached, forming a contact potential barrier between the metal and the semiconductor, known as the Schottky barrier. When the external voltage is zero, the electron diffusion current equals the reverse drift current, achieving dynamic equilibrium. When forward bias is applied (positive voltage to the metal, negative voltage to the semiconductor), the built-in field weakens, lowering the barrier on the semiconductor side, thus forming a forward current from the metal to the semiconductor. When reverse bias is applied, the built-in field strengthens, increasing the barrier height and forming a small reverse current from the semiconductor to the metal. Therefore, like a SBD-PN junction diode, it is a nonlinear device with unidirectional conductivity.

fli electrical component principle

In addition to converting optical signals into electrical signals like photodiodes, phototransistors also amplify electrical signals. The appearance of a phototransistor is similar to that of a standard transistor. Generally, a phototransistor has only two leads—the emitter and the collector—with the base unconnected. The casing has a window to allow light entry. To increase light exposure, the base area is made large while the emitter area is small, so incident light is mainly absorbed by the base region. During operation, the collector junction is reverse-biased, and the emitter junction is forward-biased. In the absence of light, the current flowing through the device is the dark current Iceo = (1 + β) Icbo (very small), which is even smaller than the penetration current of ordinary transistors. When illuminated, a large number of electron-hole pairs are generated, increasing the base current Ib. The current flowing through the device at this time is called the photocurrent, and the emitter current Ie = (2 + β) Ib. Thus, phototransistors have higher sensitivity than photodiodes.

fli electrical component principle

The construction of a mercury switch is very simple. It consists of a sealed cylindrical insulating housing containing approximately one-fifth mercury. Two wires leading out from the inside are fixed at one end of the housing. This constitutes a mercury switch. Due to gravity, the mercury bead flows to the lower part of the container. If it simultaneously contacts both electrodes, the switch closes the circuit, turning the switch on. The shape of the container also affects the conditions under which the mercury bead contacts the electrodes.

Weidou Intelligent Technology specializes in selling German fli connectors, fli switches, fli relays, fli controllers, fli plugs, fli sensors, fli resistors, fli capacitors, fli buses, fli modules, fli cables, fli power supplies, fli interfaces, fli gateways, and fli circuit breakers. fli products are original imports from Germany. Customers are welcome to inquire and place orders.