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silicon control rectifier -scr
Content
Introduction
What is SCR ?
Characteristic of SCR
Two transistor analog connection
Series connection of SCR
Parallel connection of SCR
Advantages
Disadvantages
Conclusion
Silicon Controlled Rectifiers
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attachment=35896]
A Silicon Controlled Rectifier (or Semiconductor Controlled Rectifier) is a four layer solid state device that controls current flow
The name “silicon controlled rectifier” is a trade name for the type of thyristor commercialized at General Electric in 1957
An SCR can be seen as a conventional rectifier controlled by a gate signal
It is a 4-layered 3-terminal device
When the gate to cathode voltage exceeds a certain threshold, the device turns 'on' and conducts current
Reviews
A SCR is essentially a diode with an extra terminal added
This extra terminal is called the gate, and it is used to trigger the device into conduction by the application of a small voltage
Application: DC Motor Driver
DC motor speed generally depends on a combination of the voltage and current flowing in the motor coils and the motor loads or braking torque
The speed of the motor is proportional to the voltage, and the torque is proportional to the current
DC Motors Current Driver
A rectifier is one or more diodes arranged for converting AC to DC
The current used to drive the DC motor typically comes from :
Fixed voltage:
Battery
Voltage regulator
Adjustable voltage:
PWM current source
Silicon controlled rectifier modulated AC source
Silicon Controlled Rectifiers
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attachment=63452]
A Silicon Controlled Rectifier (or Semiconductor Controlled Rectifier) is a four layer solid state device that controls current flow
The name “silicon controlled rectifier” is a trade name for the type of thyristor commercialized at General Electric in 1957
The operation of a SCR can be understood in terms of a pair of tightly coupled Bipolar Junction Transistors
SCR has three states:
Reverse blocking mode, forward blocking mode, and forward conducting mode
Reviews
A SCR is essentially a diode with an extra terminal added
This extra terminal is called the gate, and it is used to trigger the device into conduction by the application of a small voltage
DC Motors Current Driver
A rectifier is one or more diodes arranged for converting AC to DC
The current used to drive the DC motor typically comes from :
Fixed voltage:
Battery
Voltage regulator
Adjustable voltage:
PWM current source
Silicon controlled rectifier modulated AC source