BT151 Rectifier: Circuit, Pinout, and Datasheet

The BT151 is a medium power 12A silicon-controlled rectifier that comes in a TO-220 package that can be used to switch medium power AC/DC loads and can handle high DC pulses.

The BT151 is a planar passivated Silicon Controlled Rectifier in a SOT78 plastic package designed for applications requiring excellent thermal cycling performance and good bidirectional blocking voltage capability.

Pinout

Symbol

Footprint

3D Model

• High thermal cycling performance

• Good bidirectional blocking voltage capabilities

• Maximum anode-cathode voltage (off state): 650V

• Maximum RMS current: 12A

• Pulsed DC current: 120A

• Gate trigger current: 15mA max

• Holding current: 20mA max

• Latching current: 40mA max

• Available in the TO-220AB package

The BT151 can be used to give pulsed DC current to various appliances as a rectifier. A basic dimming circuit for controlling the brightness of a lamp is shown in the diagram below.

Dimming Circuit

The 10K variable resistor and 1uF capacitor operate as an RC time delay, allowing the load to regulate how much of one AC half cycle is seen. As a result, the SCR serves as an effective power controller.

DC Power Switching

Thyristors can switch low voltage low current devices as well as extremely large currents at mains (line) voltages, and they can regulate AC or DC loads. The image above shows a simple example of a thyristor managing a DC load, such as a small DC motor. A BT151 thyristor is used to link the motor to a 12V DC supply, however, it will not run until the thyristor is made to conduct. This is accomplished by briefly shutting the start switch, which sends a pulse of current to the thyristor's gate terminal. The motor now runs as soon as the thyristor is turned on, and its resistance has plummeted.

There is no gate current when the start switch returns to its normally open state, but the thyristor continues to conduct, and in a DC circuit, the current continues to flow and the motor continues to drive. Any subsequent operations on the start switch are now ineffective. Only if the current flow falls below the thyristor's holding current threshold will the thyristor turn off.

This is accomplished by briefly shutting the stop switch, which shorts out the thyristor. Because the SCR current is now less than the holding current value, the circuit current now passes through the stop switch rather than the thyristor, which turns off instantly. A normally closed switch in series with the thyristor may also be used to stop the motor. When pressed, the normally closed switch would also momentarily stop current flow through the thyristor, allowing the thyristor to turn off.

• Voltage Regulation

• Ignition Circuits

• Motor Control

• Protection Circuits

• Static Switching

Package

WeEn Semiconductors Co., Ltd is a Chinese semiconductor company based in Shang, China. It was created in January 2016 and is registered in Nanchang, China. In Jilin, Shanghai, Hong Kong, the United Kingdom, and other places, it has expanded its subsidiaries and branches. WeEn is committed to providing a broad range of innovative bipolar power products based on their cutting-edge bipolar power technology. 

Silicon-controlled rectifiers, power diodes, high voltage transistors, and silicon carbide are among the goods that are widely utilized in markets such as automotive, telecommunications, computers and consumer electronics, intelligent home appliances, lighting, and power management. They want to improve China's development by making manufacturing more intelligent and cost-effective.