SCR (Thyristor) Basics and Manufacturers

This page covers SCR (Thyristor) basics and provides a list of SCR or thyristor manufacturers.

SCR (Thyristor) is a four-layer semiconductor device having three terminals. It’s called an SCR because it’s a rectifier that can control the power supplied to a load with very little energy wastage.

When an SCR is forward biased, it doesn’t conduct until a positive voltage is applied to the gate terminal. Conduction continues even after the gate voltage is removed, typically stopping only when the supply voltage is switched off or reversed, or when the anode current falls below a certain value.

Figure 2 (as referenced in the original text, presumably the second image) depicts DC power control using the SCR (thyristor). In this circuit, when switch S1 is closed, the lamp L stays off. When switch S2 is closed, gate current flows, which fires the SCR and lights the lamp. When S2 is opened, the lamp turns off.

SCR (Thyristor) Manufacturers

• INSEL Rectifiers India Pvt. Ltd.
• Semitronics
• Infineon Technologies
• NTE
• ST Microelectronics
• Central Semiconductor
• Powerex