ELECTRONIC CONTROLS INTRODUCTION - AFP 14-X3
The AFP 14-X3 has a solid state control circuit for all timing and temperature
control functions. Three circuit boards contain the circuitry. They are the power board
([PC] Assembly--Power 115/230vac), the temperature board (PC Assembly--Control,
Temperature), and the timing board (PC Assembly - Control, Timing).
a. Power Board Function. Refer to figure 4-1.
The power board is a low voltage supply.
(a) It provides +20vdc unregulated which is used to operate the
replenisher, drive, and blower relays, as well as the feed light and audible signal.
(b) The unregulated +20vdc power is supplied to the temperature
board where it is separately regulated, as well as to an additional +12vdc regulator on
the power board.
The +12vdc regulator:
(a) Powers the zero crossing detection circuit on the power board. The
zero crossing detection circuit generates firing pulses for the triacs in conjunction with
the temperature board logic.
(b) Provides regulated power to the timing board.
There are NO adjustments on the power board.
b. Temperature Control Board Function. Refer to figure 4-2.
The temperature board controls:
(a) The power level of the developer heater. (The developer heater
indirectly controls the fixer temperature.)
(b) The power level of the dryer heater. The dryer heater has a
standby temperature control to reduce the power delivered to the dryer during the
(c) The power sharing between the developer and dryer heaters limits
the line current draw.