An electrical circuit is a simplified representation of an electric circuit element. This  uses standard symbols for the components in the circuit and does not show the physical arrangements of the components. Daily life on the earth is nearly impossible without electricity use. Homes to big industries we depend on electricity. Electric current flows in a closed circuit loop. It is a closed loop in which continuous electric current goes from the supply to the load equipment. When we want to explain a lighting circuit, it takes more time to draw the all components because, different people draw various components of the circuit in different ways and this may take a long time to explain all equipment. It’s better to learn how to show simple Circuit Projects circuit layouts. Let’s give the drawings for some simple electrical circuits.

## Electrical Circuits For Mini Projects For Engineering Students

#### AC Circuit for Lamp

The lamp requires two wires to glow, one is the neutral wire and the other one is the live wire. These two wires are connected from the lamp to the main supply panel. It is advisable to use red and black color wires for live and neutral wires in an Electrical Circuit Projects, where red color is used for live wire and black color is used for neutral wire. A switch is used to control the circuit by switching ON and OFF.
AC Circuit for Lamp

It is provided in the live wire between the main supply and load. When the switch goes ON electric circuit is closed and the lamp glows and when the switch is OFF light will disconnect the power supply to the load. This wiring is placed in a box called a switch box for better operation. Switch wire and live wire are a single wire and it is just cut in between to connect the switch.

#### Battery Charging Circuit

The battery charging is done by means of a rectifier and we know the main function of the rectifier is to convert AC into DC. The rectifier shown in the diagram is the bridge rectifier that has four diodes connected in the form of a bridge.
Battery Charging Circuit

We use this in Simple Electrical Circuit Projects. A resistance is added in the circuit to limit the flow of current. Supply is given to the rectifier through a step down transformer that converts the AC supply into DC supply and this flows to the battery. Generally, this circuit is enclosed in a battery charger unit or inverter and only the terminals emerge out of the charger unit to be connected to the battery to charge.

#### Electric Circuit for Air Conditioning

Air conditioning is a process that circulates air together with the control of its moisture. The electric aspect of AC comprises the power equipment for motors and starters for the compressor and condenser fan equipment. Electrical equipment includes solenoid valves, pressure switch, together with the safety cut-out for over current.
Air Conditioning Electric Circuit

The compressor and condenser fans are driven by a simple fixed speed-3 phase AC induction motor  with its own starter and supplied from a distribution board. The routine electric maintenance and fault finding on the motor and starters involves cleaning and checking of connections.

#### Switch Circuit

Many times in a day, we use switch buttons, but we usually don’t try to see the connection made inside the switch operation. The function of the switch is to connect or complete the circuit going to the Load from the supply and move contacts which are normally open.
Switch Circuit

The power supply to the load is through the switching circuit and therefore the power supply can be cut by keeping the switch open.

#### DC Lighting Circuit

For a small LED we use a DC supply, that has two points they are anode and cathode. The anode is positive and cathode is negative. A lamp has two terminals  one is positive and the other is negative. The positive terminal of the lamp is connected to the anode and the negative terminal of the lamp is connected to the cathode of the battery.
DC Lighting Circuit

When the connection is made the lamp will glow. Connect a switch in between any one wire that will cut off or supply DC voltage to the LED bulb.
We discussed about a few simple electrical circuits, let’s continue a few simple electrical devices. Also see the circuit functioning and uses of these devices.

#### Thermocouple Circuit

An EMF is generated  when the junctions formed from two dissimilar homogenous materials are exposed to the temperature difference. It is called the Seebeck effect. A thermocouple that consists of two wires.
Thermocouple Circuit

The voltmeter will measure the EMF generated and this can be calibrated to measure the temperature.  This difference between the hot and cold junction will produce an EMF proportional to it. When the cold junction temperature is kept constant, then the EMF is proportional to the temperature of the hot junction.

#### Energy Meter

Energy is the total power consumed over a time interval period. This can be measured by a motor meter or energy meter. These energy meters are used in all power supply lines to every house in order to measure the power consumed in both DC and AC circuits. Here energy is measured in watt-hour or kilowatt hour. In D.C power the meter may be an ampere hour or a watt-hour meter. An aluminium disc will rotate continuously when power is consumed.
Energy Meter

Speed of rotation will proportional to the power consumed by the load in watt hour. These will have a pressure coil and a current coil. The voltage is applied across the pressure coil. Current flows through the coil and produces a flux which exerts torque on the disc. The Load current flows through the current coil and produces another flux which exerts an opposite torque on the aluminium disc and resultant torque acts on the disc. Results in a rotation on the disc, which is proportional to the energy utilized and which is recorded.

#### Multimeter Circuit

A multimeter is probably one of the most simple electrical device. Which measures currents, resistance and voltage. The multimeter is an indispensable instrument and can be used for measuring DC as well as AC parameters. It is used for checking the continuity of a circuit by ohm meter scale.
Multimeter Circuit

Multimeter consists of a galvanometer connected in series with a resistance. The Voltage across the circuit can be measured by connecting the terminals of the multimeter across the circuit. This is Mainly used to test the continuity of the windings in a motor.

Therefore, this is all about Simple electrical Circuits Projects for engineering students, these basic circuits are designed by using various electrical and electronic components and these circuits are very helpful to build the electrical projects. We hope that you have got an idea about the electrical circuits.Furthermore, any queries regarding this concept or electronics projects, you can approach us by commenting in the comment section below. Here is a question for you, what is the full form of KVAR?

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