Introduction: Trick gadgets in power electronics
Silicon-controlled rectifiers (SCRs), also known as thyristors, are semiconductor power tools with a four-layer triple junction framework (PNPN). Considering that its introduction in the 1950s, SCRs have been widely utilized in commercial automation, power systems, home device control and other fields as a result of their high withstand voltage, large current lugging capacity, fast action and easy control. With the advancement of technology, SCRs have actually evolved right into numerous types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences in between these kinds are not only shown in the structure and functioning concept, but also determine their applicability in different application scenarios. This article will certainly start from a technological perspective, incorporated with particular criteria, to deeply examine the major distinctions and typical uses of these 4 SCRs.
Unidirectional SCR: Standard and secure application core
Unidirectional SCR is the most standard and usual type of thyristor. Its structure is a four-layer three-junction PNPN plan, consisting of three electrodes: anode (A), cathode (K) and gate (G). It only allows current to stream in one direction (from anode to cathode) and turns on after the gate is activated. As soon as activated, also if the gate signal is eliminated, as long as the anode current is greater than the holding present (usually less than 100mA), the SCR remains on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and existing tolerance, with an ahead repetitive top voltage (V DRM) of approximately 6500V and a rated on-state average present (ITAV) of as much as 5000A. Therefore, it is widely used in DC electric motor control, commercial heating systems, uninterruptible power supply (UPS) correction components, power conditioning gadgets and various other celebrations that need constant transmission and high power processing. Its benefits are easy structure, inexpensive and high integrity, and it is a core component of lots of typical power control systems.
Bidirectional SCR (TRIAC): Perfect for air conditioning control
Unlike unidirectional SCR, bidirectional SCR, additionally called TRIAC, can accomplish bidirectional conduction in both favorable and unfavorable half cycles. This framework includes 2 anti-parallel SCRs, which enable TRIAC to be caused and activated any time in the a/c cycle without changing the circuit connection technique. The in proportion conduction voltage variety of TRIAC is usually ± 400 ~ 800V, the maximum lots current is about 100A, and the trigger current is much less than 50mA.
Because of the bidirectional conduction attributes of TRIAC, it is especially ideal for air conditioner dimming and rate control in family appliances and customer electronic devices. For instance, gadgets such as lamp dimmers, fan controllers, and a/c unit fan rate regulators all count on TRIAC to attain smooth power regulation. Additionally, TRIAC likewise has a reduced driving power requirement and is suitable for incorporated style, so it has actually been widely used in clever home systems and tiny appliances. Although the power thickness and switching speed of TRIAC are not as good as those of new power devices, its affordable and convenient usage make it a crucial gamer in the field of tiny and moderate power a/c control.
Gateway Turn-Off Thyristor (GTO): A high-performance representative of energetic control
Entrance Turn-Off Thyristor (GTO) is a high-performance power gadget established on the basis of conventional SCR. Unlike common SCR, which can only be shut off passively, GTO can be switched off proactively by applying an adverse pulse current to the gate, therefore accomplishing even more adaptable control. This function makes GTO perform well in systems that call for frequent start-stop or quick feedback.
(Thyristor Rectifier)
The technological criteria of GTO show that it has exceptionally high power managing capability: the turn-off gain is about 4 ~ 5, the optimum operating voltage can get to 6000V, and the maximum operating current depends on 6000A. The turn-on time is about 1μs, and the turn-off time is 2 ~ 5μs. These performance signs make GTO extensively made use of in high-power scenarios such as electrical engine traction systems, large inverters, commercial motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively complicated and has high changing losses, its efficiency under high power and high vibrant feedback needs is still irreplaceable.
Light-controlled thyristor (LTT): A trusted selection in the high-voltage seclusion atmosphere
Light-controlled thyristor (LTT) utilizes optical signals as opposed to electrical signals to trigger transmission, which is its most significant function that differentiates it from other sorts of SCRs. The optical trigger wavelength of LTT is generally between 850nm and 950nm, the reaction time is gauged in milliseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic isolation system greatly boosts the system’s anti-electromagnetic interference ability and safety.
LTT is primarily utilized in ultra-high voltage direct existing transmission (UHVDC), power system relay security devices, electromagnetic compatibility protection in medical tools, and armed forces radar interaction systems etc, which have incredibly high demands for safety and security and stability. For instance, numerous converter terminals in China’s “West-to-East Power Transmission” task have actually embraced LTT-based converter shutoff components to ensure stable operation under very high voltage conditions. Some progressed LTTs can likewise be combined with gate control to accomplish bidirectional transmission or turn-off functions, even more expanding their application variety and making them a perfect selection for resolving high-voltage and high-current control issues.
Supplier
Luoyang Datang Energy Tech Co.Ltd focuses on the research, development, and application of power electronics technology and is devoted to supplying customers with high-quality transformers, thyristors, and other power products. Our company mainly has solar inverters, transformers, voltage regulators, distribution cabinets, thyristors, module, diodes, heatsinks, and other electronic devices or semiconductors. If you want to know more about silicon controlled rectifier price, please feel free to contact us.(sales@pddn.com)
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