Lowering the chair.
(a) You lower the chair through much of the same circuitry as raising.
Power is applied to the mode switch (still in manual) to the tie point in the junction.
From there it flows along the lower black wire to the foot switch. With the foot switch
closed to the "lower" position, power is applied through the switch, out of the blue wire
to the manual "lower" limit switch. It then goes to the motor and out the neutral white
(b) When you use the push button switch, power from the mode switch
is applied along the black wire to the tie point, along the middle black wire to the
common of the base switch. It then flows through the down position (1) along the white
wire to a tie point in the junction box. From there it goes along a blue wire to pin 4 of
the terminal strip. It then flows to the manual down limit switch to the motor.
Tilting the seat up.
(a) You can tilt the seat up from either the doctor's or the assistant's
side of the chair. Zero voltage is applied from the incoming neutral wire to a tie point in
the junction box to one side of the motor. 125v is brought to the other side of the motor
through the black wire to the mode switch. With the switch in the manual position,
power is applied to the tie point in the junction box, along the top wire to the common of
the back adjust switch.
(b) The assistant's and the doctor's seat adjust switches are parallel to
each other. The commons of all four switches are tied together. From the common of
the seat adjust switch, continuity is maintained through the switch to the red wire, pin 3
of the switch to the junction box. From the tie point in the junction box, power is applied
along the red wire to the operate up windings of the seat motor, energizing the motor
and tilting the seat. A screw shaft protrudes from the bottom of the motor. As the motor
turns, the shaft tilts the seat back by turning inside a plastic sleeve.
This mechanical action tilts the seat up or down, depending on the
direction of travel.
(4) Tilting the seat down. 125v is applied to the junction box, through the
mode switch to the common of the seat adjust switch. When you select down, power is
applied out the orange wire from switch pin (1) to the junction box, along the brown wire
to the exit down windings. It energizes the motor and lowers the seat.