Yes, I was going to suggest a projectred timer as well - if your modpack has it.
As for computercraft:
Code:
--Infinite loop - do the stuff inside over and over again
while true do
--send a 1-second redstone signal
redstone.setOutput("front", true)
sleep(1)
redstone.setOutput("front", false)
--wait 10 seconds to do it again
os.sleep(10)
end
Replace the button with the turtle, facing the line of redstone.
This actually does it every 11 seconds - due to the 1 extra second of sending the signal ("pressing a button"), so there will be 10 seconds of "off". If the 10 seconds is time-critical (that is, you need 10 seconds between Rising Signals), change the os.sleep(10) to 9.