other parameters can be changed via the keypad or via
the USB interface. You can also adjust the time, end
temperature, and power rating of the oven for each phase
of the reflow cycle, as well as emulate the controller
keypad via this interface.
Pressing the start button gets the process under way.
The controller provides status info on a two-line backlit
LCD display giving the cycle name, time, and temperature
so that you will know how things are progressing. For
repeat cycles, the controller will not allow you to start
another cycle until the thermal sensor cools to about 45°C
(Figure 20). The warning says “To Hot” which does mean
that the oven is too hot. This is reasonable since the PCB
needs to be cool enough to handle so you can remove it
from the oven before loading in a new board.
At the end of the cycle, the controller beeps to let
you know it’s complete. Figure 21 shows the status
display at the end of the cycle — note the elevated
temperature reading. At this point, you should open the
door to allow the oven to cool. (I found myself wishing the
door would open automatically which is an unreasonable
request. After watching the oven like a hawk for the first
few cycles, it worked so well and so predictably that I
would be off doing something else when the end-of-cycle
beep occurred.) This is a huge time saver over monitoring
time and controlling temperature manually. Of course, it’s
always a bit exciting to watch and monitor every detail of
a new process. I did carefully observe the first time I used
the reflow controller, noticing the stages the controller
went through, the time of each cycle, watching through
the glass door of the oven as the solder started to melt,
and opening the door at the end of the cycle.
January 2015 51
Figure 18. Controller ready to start the cycle.
Figure 19. USB indicators. They illuminate when the controller is on.
Figure 20. "To Hot" error message.
Figure 21. End of cycle indication. High temperature is the clue that this
is the end of the cycle.