gistfile1.js

var EventEmitter = require('events').EventEmitter;
var util = require('util');

var Ticker = function(){};

util.inherits(Ticker, EventEmitter);

Ticker.prototype.tick = function() {
    self = this;
    interval = setInterval(function() {
        self.emit('tick');
    }, 1000);
};

var myTicker = new Ticker();

myTicker.on('tick', function() {
    console.log('TICK');
});

myTicker.tick();