Get premium membership and access questions with answers, video lessons as well as revision papers.
Solid-state relays
A solid-state relay conducts load current through one or more power transistors or
thyristors.
There are three main types of SSRs, classified by the type of input.
Reed-relay coupled SSRs send the input signal through the coil of a reed relay.
Closure of the reed switch triggers the thyristor into conduction.
Transformer-coupled SSRs send an ac control signal through the primary of a small
transformer. (In the case of dc control signals, the input first goes through a DC/AC
converter before hitting the transformer primary). Voltage from the transformer
secondary triggers the thyristor.
Finally, photo coupled SSRs isolate the input from the output through a
photosensitive diode or transistor. A control current actuates a light source which in
turn, lets a photosensitive semiconductor conduct trigger-current to actuate the power
device.
gregorymasila answered the question on February 22, 2018 at 16:51
- What are the two advantages of stepper motors? Give a few applications of them &
explain permanent magnet stepper motors(Solved)
What are the two advantages of stepper motors? Give a few applications of them &
explain permanent magnet stepper motors
Date posted: February 22, 2018. Answers (1)
- Explain the different methods of starting an induction motor.(Solved)
Explain the different methods of starting an induction motor.
Date posted: February 22, 2018. Answers (1)
- What are the two types of constructions that are employed in synchronous machines?
Explain the two machines and give with reasons which of them are simple...(Solved)
What are the two types of constructions that are employed in synchronous machines?
Explain the two machines and give with reasons which of them are simple to model
and analyze
Date posted: February 22, 2018. Answers (1)
- Explain the construction and working principle of a transformer(Solved)
Explain the construction and working principle of a transformer
Date posted: February 22, 2018. Answers (1)
- Write short note on Differential Relay(Solved)
Write short note on Differential Relay
Date posted: February 22, 2018. Answers (1)
- Write short note on Application of dielectric heating(Solved)
Write short note on Application of dielectric heating
Date posted: February 22, 2018. Answers (1)
- Describe the construction, principle of operation and advantages of SF6 circuit
breaker.(Solved)
Describe the construction, principle of operation and advantages of SF6 circuit
breaker.
Date posted: February 22, 2018. Answers (1)
- Write short note on following: (a) Condenser in Thermal power plant (b) Control of nuclear reactor(Solved)
Write short note on following:
(a) Condenser in Thermal power plant
(b) Control of nuclear reactor
Date posted: February 22, 2018. Answers (1)
- Explain the principle of operation of two phase servo motor. Draw its torque-slip characteristics.(Solved)
Explain the principle of operation of two phase servo motor. Draw its torque-slip characteristics.
Date posted: February 22, 2018. Answers (1)
- (a) Why does the induction motor not rotate at synchronous speed?
(b) Describe with the aid of diagram of connection, phasor diagram and torque-slip
characteristics, the...(Solved)
(a) Why does the induction motor not rotate at synchronous speed?
(b) Describe with the aid of diagram of connection, phasor diagram and torque-slip
characteristics, the working of capacitor-start single phase induction motor.
Date posted: February 22, 2018. Answers (1)
- Explain two important functions served by the damper winding in a synchronous motor. State the various applications of synchronous motor(Solved)
Explain two important functions served by the damper winding in a synchronous motor. State the various applications of synchronous motor.
Date posted: February 22, 2018. Answers (1)
- Write short notes on Switched reluctance motor(Solved)
Write short notes on Switched reluctance motor
Date posted: February 22, 2018. Answers (1)
- What are the advantages of high voltage transmission and its limitations(Solved)
What are the advantages of high voltage transmission and its limitations
Date posted: February 22, 2018. Answers (1)
- What are the criteria for the classification of transmission lines as short, medium and long lines?(Solved)
What are the criteria for the classification of transmission lines as short, medium and long lines?
Date posted: February 22, 2018. Answers (1)
- Describe the construction of a lead acid cell and explain the process of charging and discharging of the cell(Solved)
Describe the construction of a lead acid cell and explain the process of charging and discharging of the cell.
Date posted: February 22, 2018. Answers (1)
- Write notes on the following
(i) Differential relays.
(ii) Inductive interference in a transmission line.
(iii) Nickel-cadmium cells.(Solved)
Write notes on the following
(i) Differential relays.
(ii) Inductive interference in a transmission line.
(iii) Nickel-cadmium cells.
Date posted: February 22, 2018. Answers (1)
- Describe a typical coreless type of induction furnace and its special features(Solved)
Describe a typical coreless type of induction furnace and its special features
Date posted: February 22, 2018. Answers (1)
- Describe the primary and back-up protection features that are provided for transmission lines(Solved)
Describe the primary and back-up protection features that are provided for transmission lines.
Date posted: February 22, 2018. Answers (1)
- List out the important advantages of HVDC transmission(Solved)
List out the important advantages of HVDC transmission
Date posted: February 22, 2018. Answers (1)
- Give a list of the factors involved for selecting a factory drive(Solved)
Give a list of the factors involved for selecting a factory drive
Date posted: February 22, 2018. Answers (1)