AAM103 - Industrial Electronics - Silicon Controlled Switch (SCS) PDF

AAM103 - Industrial Electronics Silicon Controlled Switch (SCS) Reporters: Abad, Cyrus Joshua Respuesto, Shaina Jane College of Engineering & Technology MSU-Iligan Institute of Technology   Silicon Controlled Switch (SCS)...

AAM103 - Industrial Electronics Silicon Controlled Switch (SCS) Reporters: Abad, Cyrus Joshua Respuesto, Shaina Jane College of Engineering & Technology MSU-Iligan Institute of Technology   Silicon Controlled Switch (SCS) ⮚ like the SCR, is a unilateral, four layer, three junction P-N-P- N silicon device with four electrodes. ⮚ is a low power device compared with the SCR. It handles currents in milliamperes rather than amperes. Bachelor of Science in Industrial Automation and Mechatronics   Physical Diagram Bachelor of Science in Industrial Automation and Mechatronics   Schematic Symbol Bachelor of Science in Industrial Automation and Mechatronics   Equivalent Schematic Bachelor of Science in Industrial Automation and Mechatronics   SCS Functions 3. Conducting State 1. Off State (Blocking State) 2. Turning On 4. Turning Off Bachelor of Science in Industrial Automation and Mechatronics   Main purposes of an SCS: 1. Switching Applications: SCS is primarily used in switching circuits where it can act as a bistable switch. It can turn on or off based on external control signals applied to its gates. 2. Power Control: It controls large power loads with small gate currents, making it useful in power regulation and motor control applications. Bachelor of Science in Industrial Automation and Mechatronics   Main purposes of an SCS: 3. Pulse Circuits: It is often used in pulse-generating circuits, such as in oscillators and timers. 4. Overload Protection: In some applications, SCSs can be used to protect circuits by shutting off when excessive current is detected. 5.Logic Circuits: Because of its latching behavior, it finds applications in logic circuits and memory elements where a stable on-off state is required. Bachelor of Science in Industrial Automation and Mechatronics   How does SCS works? Bachelor of Science in Industrial Automation and Mechatronics Bachelor of Science in Industrial Automation and Mechatronics   ADVANTAGES 1. High Current and Voltage Handling: SCSs can handle higher currents and voltages compared to other transistor-like devices. 2. Great Electrical Efficiency: Due to their operational structure, once an SCS is latched on (activated), it stays on even if the gate signal is removed, until the main current drops below a critical holding level. 3. Control over Switching: An SCS provides control over both the turn-on and turn-off of the device. Bachelor of Science in Industrial Automation and Mechatronics   ADVANTAGES 4. Withstand Adverse Conditions: SCSs are capable of withstanding harsh operating conditions, such as high temperatures. This, combined with their ruggedness and longevity, makes them suitable for a wide range of applications, particularly in industrial settings. 5. Low Switching Losses: SCSs have low switching losses, which makes them efficient for applications where switching is frequent. 6. Noise Immunity: SCSs are quite immune to noise because of the latching feature. Bachelor of Science in Industrial Automation and Mechatronics   DISADVANTAGES 1. Unidirectional Conduction: In their most common forms, SCS are unidirectional devices, they allow current to flow only in one direction, from anode to cathode. 2. Gate Control Limitations: Turning off an SCS can often require complex sequences, especially for larger power thyristors. 3. Not Suitable for Low Power Applications: Due to their high power handling capacity, SCS are not typically suited for low power applications. They are more often found in power electronics. Bachelor of Science in Industrial Automation and Mechatronics   DISADVANTAGES 4. Switching Speed: While SCS devices are good at handling high voltages and currents, they are not as fast as some other switching devices, such as certain types of transistors. 5. Sensitivity to Elevated Temperatures: Although SCS are designed to tolerate higher operating temperatures than most semiconductor devices, they can malfunction or suffer thermal runaway if these temperatures are exceeded. 6. Overcurrent Damage: SCS are subject to damage from overcurrent conditions. This can arise from excessive load, short circuits, or transients such as power surges. Bachelor of Science in Industrial Automation and Mechatronics  APPLICATIONS Bachelor of Science in Industrial Automation and Mechatronics   Silicon Controlled Switch (SCS) is used in pulse generators, voltage sensors, counters, timing, logic and triggering circuits.  The device is used in lamp drivers, power switching circuits, and logic circuits as well as in essentially any circuit that requires as witch that can be turned ON and OFF by two separate control pulses. Bachelor of Science in Industrial Automation and Mechatronics  DIFFERENCE Bachelor of Science in Industrial Automation and Mechatronics  SCS AND SCR SCR (Silicon Controlled SCS (Silicon Controlled Feature Rectifier) Switch) Three (Anode, Cathode, Four (Anode, Cathode, Gate, Terminals Gate) Anode Gate) Can be turned on via gate; Can be turned on and off via Control cannot be turned off via gate and anode gate gate Can be turned off by Turns off when current drops Turn-off Mechanism applying a signal to the below holding current anode gate AC/DC rectifiers, motor Precision switching, pulse Applications control, power control circuits, logic circuits Less control; only turned on More control; can be turned Versatility by gate on and off by signals Bachelor of Science in Industrial Automation and Mechatronics  SCS AND DIAC SCS (Silicon Controlled DIAC (Diode for Feature Switch) Alternating Current) Four (Anode, Cathode, Gate, Two (Anode, Cathode or Terminals Anode Gate) simply two terminals) No gate, triggered by Gate control for turning Control exceeding breakover on/off voltage Unidirectional (current flows Bidirectional (current flows Bidirectional in one direction) in both directions) Power control, switching Triggering TRIACs in AC Applications circuits circuits Cannot be turned off, Can be turned off by returns to non-conductive Turn-off mechanism negative gate current state when current drops below holding current Bachelor of Science in Industrial Automation and Mechatronics   REFERENCE https://www.allaboutcircuits.com/textbook/semiconductors/chpt- 7/silicon-controlled-switch-scs/#:~:text=This%20extra%20termin al%20allows%20more,below%20the%20holding%20current%20 value. https://slideplayer.com/slide/15265232/ https://www.ntchip.com/electronics-news/silicon-controlled-switc h https://www.eeeguide.com/silicon-controlled-switch-scs/ https://www.scribd.com/doc/304937484/Silicon-Controlled- Switch Bachelor of Science in Industrial Automation and Mechatronics   REFERENCE YOUTUBE: https://www.youtube.com/watch?v=es6RlYVoeKs&t=700s https://www.youtube.com/watch?v=sEinncLAqiY Bachelor of Science in Industrial Automation and Mechatronics