Types of Circuit Breaker

It depends what circuit you are making. 
Circuit breakers come in different 'ratings' and so are chosen according to the power demands of the circuit you have.
You don't choose a circuit for a circuit breaker as such, you choose a circuit breaker according to what circuit you have made.
There are several type of circuit breakers now a day we are using these are as follows:

1. M.C.B. (Miniature circuit Breaker)
Rating : 1, 2, 4, 6, 10, 16, 20, 25, 32, 63 Amperes

2. M.C.C.B. (Molded case circuit Breaker)
Rating : 10, 16, 20, 25, 32, 63, 100, 200, 250, 400 Amperes.

3. A.C.B. (Air Circuit Breaker)
Rating : 400, 800, 1000, 1200, 1500, 1800, 2000 Amperes.

4. A. B. Switch (Air Breaker)
used in High tension line.

5. SF6 Breaker (Contact break in the Sf6 medium)
used in High tension line.

mcb internal circuit shown in figure ....

What is a Solenoid Valve?

What is a Solenoid Valve? How does a Solenoid Valve Work?

Solenoid valves are electrically actuated mechanical systems that control the flow of substances like liquids and gases. Solenoid valves are commonly used on automotive transmissions.The solenoid valve uses an electric current which moves the solenoid. This pulls a piston preventing it from stopping the flow of air and fluid. The valve will need a constant flow of electrical current to remain open because when there is no current flow, the electromagnetic field scatters and the valve returns to its original position.

What is AC series motor?

An AC series motor is a special type of motor, which has been designed to operate on either AC or DC power. This type of motor is also called universal motor. An advantage of the AC series motor is, this type of motor is designed to provide high starting torque and as it has very compact design so high running speeds are produced. The basic construction of an ac series motor slightly differs from the construction of a dc series motor. AC series motor has low speeds for large loads and high speeds for light loads. This type of motor is widely used in small home appliances like blower, grinder and power tools like drill machine etc.

Use of Single & 3-phase and HVDC

Most transmission lines use high-voltage three-phase alternating current (AC), although single phase AC is sometimes used in railway electrification systems. High-voltage direct-current (HVDC) technology is used for greater efficiency in very long distances (typically hundreds of miles (kilometres)), or in submarine power cables (typically longer than 30 miles (50 km)).
Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long-distance transmission. Power is usually transmitted through overhead power lines

Function of AC Drives

AC Drives are also known as Inverters, Variable Speed Drives (VSDs), Variable Frequency Drives (VFDs) and Frequency Convertors. 

AC Drives are used to control AC Induction motors; the most common motor technology used in industry. The motors are rugged, require very little maintenance and can easily be manufactured with high environmental protection.

If an AC motor is connected directly to the mains supply the motor will accelerate quickly and then rotate at a fixed speed which is dependant upon the electrical supply frequency and the motor design.

What is a thermocouple sensor?

What is a thermocouple sensor?
A thermocouple is a sensor for measuring temperature. It consists of two dissimilar metals, joined together at one end. When the junction of the two metals is heated or cooled a voltage is produced that can be correlated back to the temperature. The thermocouple alloys are commonly available as wire.

What are the different thermocouple types?
A thermocouple is available in different combinations of metals or calibrations. The four most common calibrations are J, K, T and E. There are high temperature calibrations R, S, C and GB. Each calibration has a different temperature range and environment, although the maximum temperature varies with the diameter of the wire used in the thermocouple

AC DRIVES

AC Drives are also known as Inverters, Variable Speed Drives (VSDs), Variable Frequency Drives (VFDs) and Frequency Convertors. 

AC Drives are used to control AC Induction motors; the most common motor technology used in industry. The motors are rugged, require very little maintenance and can easily be manufactured with high environmental protection. 

If an AC motor is connected directly to the mains supply the motor will accelerate quickly and then rotate at a fixed speed which is dependant upon the electrical supply frequency and the motor design.