Intro: Secret gadgets in power electronic devices

Silicon-controlled rectifiers (SCRs), also known as thyristors, are semiconductor power devices with a four-layer triple joint framework (PNPN). Since its introduction in the 1950s, SCRs have been extensively used in commercial automation, power systems, home appliance control and various other fields due to their high stand up to voltage, large current lugging ability, fast action and basic control. With the growth of innovation, SCRs have developed right into many types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions between these types are not just reflected in the framework and working principle, but additionally determine their applicability in different application scenarios. This article will begin with a technical viewpoint, combined with details criteria, to deeply evaluate the primary distinctions and common uses of these 4 SCRs.

Unidirectional SCR: Fundamental and stable application core

Unidirectional SCR is the most fundamental and common kind of thyristor. Its framework is a four-layer three-junction PNPN plan, including three electrodes: anode (A), cathode (K) and gateway (G). It only permits current to stream in one direction (from anode to cathode) and switches on after eviction is set off. As soon as activated, even if eviction signal is eliminated, as long as the anode current is higher than the holding existing (usually much less than 100mA), the SCR continues to be on.

(Thyristor Rectifier)

Unidirectional SCR has strong voltage and present tolerance, with an ahead repeated optimal voltage (V DRM) of as much as 6500V and a ranked on-state typical existing (ITAV) of approximately 5000A. Consequently, it is extensively utilized in DC motor control, commercial furnace, uninterruptible power supply (UPS) correction components, power conditioning gadgets and various other occasions that require continuous transmission and high power processing. Its advantages are simple framework, affordable and high reliability, and it is a core component of lots of conventional power control systems.

Bidirectional SCR (TRIAC): Perfect for AC control

Unlike unidirectional SCR, bidirectional SCR, also referred to as TRIAC, can accomplish bidirectional transmission in both positive and negative half cycles. This structure consists of 2 anti-parallel SCRs, which enable TRIAC to be triggered and turned on at any moment in the air conditioning cycle without changing the circuit link technique. The in proportion conduction voltage range of TRIAC is generally ± 400 ~ 800V, the optimum load current is about 100A, and the trigger current is much less than 50mA.

As a result of the bidirectional transmission qualities of TRIAC, it is especially ideal for air conditioning dimming and rate control in home appliances and consumer electronics. As an example, devices such as lamp dimmers, follower controllers, and air conditioning unit fan speed regulatory authorities all depend on TRIAC to attain smooth power law. In addition, TRIAC additionally has a lower driving power demand and appropriates for incorporated style, so it has been commonly utilized in clever home systems and small home appliances. Although the power density and switching speed of TRIAC are not like those of new power tools, its low cost and practical use make it an important gamer in the field of little and moderate power air conditioner control.

Gateway Turn-Off Thyristor (GTO): A high-performance rep of energetic control

Entrance Turn-Off Thyristor (GTO) is a high-performance power gadget established on the basis of typical SCR. Unlike average SCR, which can just be shut off passively, GTO can be shut off proactively by using an adverse pulse existing to eviction, therefore attaining even more adaptable control. This function makes GTO carry out well in systems that need frequent start-stop or rapid action.

(Thyristor Rectifier)

The technological parameters of GTO show that it has extremely high power dealing with capacity: the turn-off gain has to do with 4 ~ 5, the optimum operating voltage can reach 6000V, and the maximum operating current depends on 6000A. The turn-on time has to do with 1μs, and the turn-off time is 2 ~ 5μs. These performance indications make GTO commonly used in high-power situations such as electrical locomotive grip systems, big inverters, industrial motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively complex and has high switching losses, its efficiency under high power and high vibrant action needs is still irreplaceable.

Light-controlled thyristor (LTT): A dependable choice in the high-voltage seclusion environment

Light-controlled thyristor (LTT) makes use of optical signals instead of electric signals to cause conduction, which is its biggest attribute that distinguishes it from various other types of SCRs. The optical trigger wavelength of LTT is typically between 850nm and 950nm, the feedback time is determined in split seconds, and the insulation degree can be as high as 100kV or above. This optoelectronic isolation system significantly boosts the system’s anti-electromagnetic interference capability and security.

LTT is generally used in ultra-high voltage straight existing transmission (UHVDC), power system relay security devices, electro-magnetic compatibility security in medical devices, and military radar interaction systems and so on, which have incredibly high requirements for security and security. For example, several converter stations in China’s “West-to-East Power Transmission” job have taken on LTT-based converter valve components to ensure steady procedure under incredibly high voltage problems. Some advanced LTTs can additionally be combined with entrance control to accomplish bidirectional conduction or turn-off features, additionally increasing their application variety and making them a perfect option for fixing high-voltage and high-current control issues.

Vendor

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 the silicon controlled rectifier, please feel free to contact us.(sales@pddn.com)

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