Littelfuse can help you find the right circuit protection solution for your application. We are a global company and feature the broadest line of circuit protection technologies available. Littelfuse circuit protection solutions are found in a large range of products, including Telecommunications equipment, computer, automotive, consumer electronics, and industrial applications. To search through our wide range of quality products and find the overvoltage solution for your project, click here: Thyristor Product Technology and More.
To learn more about industry leading Teccor brand protection and switching thyristor products and our entire line of transient voltage suppression solutions, follow this link: Littelfuse Products.
A SIDACtor device is a PNPN device that can be thought of as a TVS diode with a gate. Upon exceeding its peak off-state voltage (VDRM), a SIDACtor device will clamp a transient voltage to within the device’s switching voltage (VS) rating. Then, once the current flowing through the SIDACtor device exceeds its switching current, the device will crowbar and simulate a short-circuit condition. When the current flowing through the SIDACtor device is less than the device’s holding current (IH), the SIDACtor device will reset and return to its high off-state impedance.
Teccor® brand sensitive gate triacs are AC bi-directional silicon switches that provide guaranteed gate trigger current levels in Quadrants I, II, III, and IV. Interfacing to microprocessors or other equipment with single polarity gate triggering is made possible with sensitive gate triacs. Gate triggering currents of 3 mA, 5 mA,10 mA, or 20 mA may be specified. Sensitive gate triacs are capable of controlling AC load currents from 0.8 A to 8A rms and can withstand operating voltages from 200 V to 600 V.
Teccor® brand triac products are bi-directional AC switches, capable of controlling loads from 0.8 A to 35A rms with 10 mA, 25 mA, and 50 mA IGT in operating Quadrants I, II and III. Triacs are useful in full-wave AC applications to control AC power either through full-cycle switching or phase control of current to the load element. These triacs are rated to block voltage in the “OFF” condition from 200 V minimum with selected products capable of 1000 V operation. Typical applications include motor speed controls, heater controls, and incandescent light controls.
Teccor® brand Quadrac devices are triacs and alternistor triacs with a diac trigger mounted inside the same package. These devices save the user the expense and assembly time of buying a discrete diac and assembling in conjunction with a gated triac. Quadrac devices are offered in capacities from 4 A to 15 A rms and voltages from 200 V ac to 600 V ac.
The Teccor® brand alternistor is specifically designed for applications required to switch highly inductive loads. The design of this special chip effectively offers the same performance as two thyristors (SCRs) wired inverse parallel (back-to-back). This new chip construction provides the equivalent of two electrically-separate SCR structures, providing enhanced dv/dt characteristics while retaining the advantages of a single-chip device. Teccor manufactures 6 A to 40 A alternistors with blocking voltage rating from 200 V to 1000V. Alternistors are offered in TO-220, TO-218, and TO-218X packages with isolated and non-isolated versions.
Teccor® brand sensitive gate SCRs are silicon-controlled rectifiers representing the best in design, performance, and packaging techniques for low- and medium-current applications. Anode currents of 0.8 A to 10 A rms can be controlled by sensitive gate SCRs with gate drive currents ranging from 12 µA to 500 µA. Sensitive gate SCRs are ideally suited for interfacing to integrated circuits or in applications where high current load requirements and limited gate drive current capabilities exist. Examples include ignition circuits, motor controls, and DC latching for alarms in smoke detectors. Sensitive gate SCRs are available in voltage ratings to 600 VAC.
Teccor® brand SCR products are half wave, silicon-controlled rectifiers that represent the state of the art in design and performance. Load current capabilities range from 1 A to 70 A rms, and voltages from 200 V to 1000 V may be specified to meet a variety of application needs. Because of its unidirectional switching capability, the SCR is used in circuits where high surge currents or latching action is required. It may also be used for half wave- type circuits where gate-controlled rectification action is required. Applications include crowbars in power supplies, camera flash units; smoke alarms, motor controls, battery chargers, and engine ignition. Surge current ratings are available from 30 A in the TO-92 packaging to 950A in the TO-218X package.
Littelfuse manufactures 15 A to 25 A rms rectifiers with voltages rated from 200 V to 1000 V. Due to the electrically isolated TO-220 package, these rectifiers may be used in common anode or common cathode circuits using only one part type, thereby simplifying stock requirements.
A thyristor is a semiconductor switch that is used as a gate circuit. The most widely used members of the thyristor family are triacs, sidacs, diacs, and silicon controlled rectifiers (SCRs). Protection thyristors are used in telecom, industrial, home appliance, TVSS, and many other applications.
For more information about the different types of thyristors and their applications, visit the Littelfuse Knowledgebase. Littelfuse associates located all over the world are also available to help you find the right thyristor or other circuit protection solution. Contact Littelfuse.
To learn more about the fundamental characteristics of thyristors, please view our Thyristor Semiconductors PDF
Additional Information:
Metal Oxide Varistors
TVSS
Resettable Fuses
Gas Discharge Tubes
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