Choke

 Choke coil

The choke coil works because it acts as an inductor. When the current passing through changes, as AC currents do, it typically creates a magnetic field in the coil that works against that current. This property, known as inductance, blocks most of the AC current from passing through.

Inductor

 The inductor is a component that allows DC, but not AC, to flow through it

Choke with starter is used in fluorescent tubelight

Filter circuit

 Filter circuit 

If the surge exceeds the normal ±180 volt peak dynamic range of the power wave, the dynamic clamp circuit (D1 C3) which tracks the peak of the power wave comes into play

Placing a diode in reverse bias in parallel to the load eliminates voltage spikes by going into conduction before a large voltage can form across the motor. And this is how a DC transientvoltage

 suppressor circuit works to eliminate 

harmful voltage spikes.

The filter circuit is used in spike

 guard to filter out the power spikes and  protect against power surges

Capacitor 

A

The capacitor allowsalternating current (AC) to pass but it blocks direct current (DC). 

Tricks

 

 

Bimetallic strip

A bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand at different rates as they are heated, usually steel and copper, or in some cases steel and brass. The different expansions force the flat strip to bend one way if heated, and in the opposite direction if cooled below its initial temperature. The metal with the higher coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled.

The bimetallic strip is used in emergency switch