Intro: Key devices in power electronic devices
Silicon-controlled rectifiers (SCRs), likewise known as thyristors, are semiconductor power devices with a four-layer three-way junction framework (PNPN). Because its introduction in the 1950s, SCRs have actually been widely utilized in commercial automation, power systems, home appliance control and other fields due to their high withstand voltage, large current carrying ability, quick feedback and easy control. With the advancement of innovation, SCRs have actually advanced into numerous kinds, including unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions between these kinds are not only mirrored in the structure and working concept, however also establish their applicability in various application circumstances. This write-up will certainly start from a technical perspective, combined with details parameters, to deeply evaluate the primary distinctions and normal uses these 4 SCRs.
Unidirectional SCR: Standard and stable application core
Unidirectional SCR is the most standard and typical type of thyristor. Its structure is a four-layer three-junction PNPN arrangement, including 3 electrodes: anode (A), cathode (K) and gate (G). It only enables existing to flow in one direction (from anode to cathode) and switches on after the gate is activated. When turned on, even if eviction signal is removed, as long as the anode current is above the holding present (normally less than 100mA), the SCR stays on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and existing tolerance, with an onward repetitive peak voltage (V DRM) of up to 6500V and a ranked on-state average existing (ITAV) of as much as 5000A. As a result, it is extensively used in DC electric motor control, commercial furnace, uninterruptible power supply (UPS) correction parts, power conditioning devices and other events that call for continuous conduction and high power handling. Its advantages are straightforward framework, affordable and high reliability, and it is a core element of numerous traditional power control systems.
Bidirectional SCR (TRIAC): Suitable for air conditioning control
Unlike unidirectional SCR, bidirectional SCR, likewise called TRIAC, can accomplish bidirectional transmission in both positive and unfavorable fifty percent cycles. This framework includes 2 anti-parallel SCRs, which enable TRIAC to be triggered and switched on at any time in the air conditioner cycle without transforming the circuit connection approach. The symmetrical transmission voltage series of TRIAC is generally ± 400 ~ 800V, the maximum lots current has to do with 100A, and the trigger current is less than 50mA.
Due to the bidirectional conduction attributes of TRIAC, it is especially suitable for air conditioning dimming and speed control in home appliances and consumer electronic devices. For instance, gadgets such as lamp dimmers, fan controllers, and air conditioning system follower rate regulators all depend on TRIAC to achieve smooth power guideline. In addition, TRIAC likewise has a reduced driving power demand and appropriates for incorporated style, so it has been extensively utilized in smart home systems and small home appliances. Although the power thickness and switching rate of TRIAC are not just as good as those of new power devices, its low cost and convenient use make it a vital gamer in the field of tiny and medium power AC control.
Gateway Turn-Off Thyristor (GTO): A high-performance rep of energetic control
Gateway Turn-Off Thyristor (GTO) is a high-performance power device developed on the basis of typical SCR. Unlike normal SCR, which can only be switched off passively, GTO can be shut off actively by using a negative pulse existing to the gate, therefore attaining more versatile control. This attribute makes GTO perform well in systems that need regular start-stop or quick action.
(Thyristor Rectifier)
The technical specifications of GTO reveal that it has very high power handling capacity: the turn-off gain is about 4 ~ 5, the optimum operating voltage can get to 6000V, and the optimum operating current is up to 6000A. The turn-on time is about 1μs, and the turn-off time is 2 ~ 5μs. These efficiency indications make GTO commonly made use of in high-power circumstances such as electric locomotive traction systems, big inverters, industrial electric motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is fairly complicated and has high switching losses, its efficiency under high power and high vibrant reaction needs is still irreplaceable.
Light-controlled thyristor (LTT): A reliable choice in the high-voltage seclusion setting
Light-controlled thyristor (LTT) utilizes optical signals instead of electrical signals to set off transmission, which is its biggest function that differentiates it from other kinds of SCRs. The optical trigger wavelength of LTT is typically between 850nm and 950nm, the response time is measured in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion system significantly boosts the system’s anti-electromagnetic interference capacity and safety.
LTT is primarily utilized in ultra-high voltage straight existing transmission (UHVDC), power system relay security gadgets, electro-magnetic compatibility protection in clinical tools, and armed forces radar interaction systems etc, which have exceptionally high requirements for safety and stability. For example, several converter stations in China’s “West-to-East Power Transmission” project have actually taken on LTT-based converter valve modules to make certain secure operation under incredibly high voltage problems. Some advanced LTTs can additionally be incorporated with gate control to achieve bidirectional transmission or turn-off functions, better broadening their application variety and making them a suitable option for addressing high-voltage and high-current control problems.
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 silicon controlled rectifier for sale, please feel free to contact us.(sales@pddn.com)
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