- > Timer facing east
- ^ Timer facing north
- # Toggle latch with the torches facing north/south
- + Wire
- R Reactor (or reactor chamber)
- Set > to the operational time and ^ to the cooldown time.
- While > is spinning, the wire going to the reactor should be off, and vice-versa - if not, right-click the toggle latch to invert.
No frills, only using 2 timers and 1 toggle.