Design a scheduler on top of delayed_job

Hi ,
      I am writing a scheduler with delayed_job as job processor. I have
a doubt whether I should run scheduler on top of delayed_job or can I
add the scheduler code on Worker.start method of delayed Job.

I want scheduler in separate thread and delayed job execution in
separate thread so that scheduler doesn't gets affected by longer
executing jobs in delayed jobs . say My scheduler should run for every
five minutes . If my delayed job takes more than 5 minutes then it
affects scheduler also . please help me in good design.