The TYN612 Unidirectional SCR (Silicon Controlled Rectifier) is a high-performance power switching component designed for AC and DC power control applications. At Electrapac, we recommend the TYN612 for its robust "A-Class" reliability, making it the ideal choice for heavy-duty industrial and hobbyist projects that require precise power regulation.

Product Overview

The TYN612 is a three-terminal semiconductor that acts as a controlled switch. Unlike a transistor, once the TYN612 is triggered by a small gate current, it remains "Latched" in the ON state until the current flowing through it drops below a specific threshold (the holding current). This makes it exceptionally efficient for phase control and surge protection.

Key Features for Electrapac Customers

• High Voltage Tolerance: Rated for 600V, the TYN612 easily handles standard 220V 240V AC mains with a significant safety margin.

• Superior Latching Performance: Optimized for high-current latching, ensuring stable operation in motor control and heating circuits.

• Rugged TO-220 Package: Designed for easy heat sink mounting. The metal tab is typically connected to the Anode, allowing for efficient thermal dissipation.

• Precision Triggering: Sensitive gate control allows it to be triggered by low-power microcontrollers (with appropriate isolation) or simple RC timing circuits.

• Surge Capability: Can withstand short-duration current spikes up to 120A, protecting your circuit during initial power-up or unexpected surges.

Technical Implementation Guide

To ensure the safety and longevity of your Electrapac project, follow these professional guidelines:

1. Thermal Management: When switching 12A, the TYN612 will generate heat. An aluminum heatsink is required for any continuous load over 2A.

2. AC Phase Control: This is a unidirectional device. In an AC circuit, it will only conduct during the positive half-cycle. If you need full-wave control, you must use two SCRs in anti-parallel or use a Bridge Rectifier.

3. Gate Protection: Always use a series resistor on the Gate to limit the trigger current. For 5V logic, a 220 to 470 resistor is commonly used.

4. Snubber Circuit: When driving inductive loads (motors or transformers), add a snubber (an RC circuit) across the Anode and Cathode to prevent accidental triggering caused by rapid voltage changes (dv/dt).

Primary Applications

• AC Motor Speed Control: Adjusting the speed of fans, drills, and industrial motors.

• Light Dimming Systems: High-power theatrical or architectural lighting control.

• Battery Chargers: Regulating the charging current for high-capacity battery banks.

• Static Switching: Replacing mechanical relays for silent, long-life power switching.

• Over-Voltage Protection: Used in "Crowbar" circuits to blow a fuse and protect downstream electronics during a power surge.

Why Shop at Electrapac?

We source the A-Class TYN612 specifically for its high dv/dt immunity and reliable gate sensitivity. Visit us at for the high-power semiconductors that give you total control over your energy.