public class Global : HttpApplication
{
    public static StdSchedulerFactory SchedulerFactory;
    public static IScheduler Scheduler;
    public static ITrigger ImageTrigger;

    protected void Application_Start(object sender, EventArgs e)
    {
        SchedulerFactory = new StdSchedulerFactory();
        Scheduler = SchedulerFactory.GetScheduler();

        Scheduler.Start();

        ImageTrigger = TriggerBuilder.Create()
                                     .WithIdentity("ImageTrigger", "Group1")
                                     .StartNow()
                                     .WithSimpleSchedule(x => x.RepeatForever().WithIntervalInMinutes(5))
                                     .Build();

        var imageJob = JobBuilder.Create<DownloadImages>()
                                     .WithIdentity("DownloadImages" , "Group1")
                                     .Build();
        Scheduler.ScheduleJob(imageJob, ImageTrigger);
    }
...
}

AlertTrigger = TriggerBuilder.Create()
                                     .WithIdentity("AlertTrigger", "Group1")
                                     .StartNow()
                                     .WithCronSchedule("0 0/1 * * * ?")
                                     .Build();