Lok Sabha Election: How does an EVM machine work? The tech aspect

An EVM machine has two units, namely, the control unit and the balloting unit. These units are connected by a cable.

The EVM's control machine is with the presiding officer, also called the polling officer. 

EVM machine runs on an ordinary 7.5 volt alkaline battery made by Bharat Electronics Ltd., allowing it to run even without electricity. 

Once you enter the polling compartment, the presiding officer presses the ballot button, and a red light titled busy glows, allowing you to vote. 

Once he does that, a green light glows on the ballot unit, letting the voter vote. 

The voter can now cast his/her vote by pressing the button next to the choice of this candidate/party. 

Once the voter casts a vote, the control unit emits a beep sound, indicating that the vote has been cast. 

After you vote, the polling officer presses a button sealing the machine, meaning no further vote can be cast. 

Once the voting is done, the VVPAT (Voter Verified Paper Audit Trail) unit generates a paper slip that is visible to the voter for 7 days.

After that, it gets cut and falls into a sealed drop box of VVPAT.

VVPAT runs on a battery pack of 15 volts.