ethereumSignTxn.js

const Web3 = require('web3');
const url = 'http://localhost:8545'; //ganache-cli rpc 
let web3 = new Web3(new Web3.providers.HttpProvider(url));
const EthereumTx = require('ethereumjs-tx').Transaction

web3.eth.getAccounts().then(accounts => {
    //sending eth using the sendTransaction. 
    web3.eth.personal.sendTransaction({
        from: accounts[1],
        gasPrice: "20000000000",
        gas: "21000",
        to:  accounts[3],
        value: "1000000000000000000",
        data: ""
    }, ).then(
        web3.eth.getBalance(accounts[3]).then(balance => {
            console.log(web3.utils.fromWei(balance, 'ether'));
        })

    );
});

let sendingAddress = '0x810614B66497f9Cf4788e50e27E690C6f4c3ab90';
let receivingAddress = '0xf293d70BDF8d2370f7Bd150c4EcAf76d977A5928';

let privKeySender = '32f95d7667f9b4a0a8bc8bd94e74c1a8b863114167431737ba1d26f50be9bc6f';

//sending a signed transaction using the private key from address.
web3.eth.accounts.signTransaction({
    nonce: web3.eth.getTransactionCount(sendingAddress),
    to: receivingAddress,
    value: '1000000000',
    gas: 2000000
}, privKeySender )
.then(data =>{console.log('data', data)});



//Using the Ethereum-tx library to sign and send transaction. Raw txn details are in hex vals
let privKeySenderHex =  new Buffer.from(privKeySender, 'hex');

const rawTxn = {
    nonce: '0x9',
    gasPrice: '0x4a717c800',
    gasLimit: '0xc340',
    to: receivingAddress,
    value: '0x2386f26fc10000',
    data: '0x'
};

var txn = new EthereumTx(rawTxn)
txn.sign(privKeySenderHex);
const serializedTxn = txn.serialize();
web3.eth.sendSignedTransaction(serializedTxn);

web3.eth.getBalance(receivingAddress).then(balance => {
    console.log(web3.utils.fromWei(balance, 'ether'));
});