-
DFC90 Autopilot Disconnects
The DFC-90 requires Aircraft Power to be supplied to "A/P Disconnect" P1-17 and "Trim Interrupt " P2-14. If either input is missing the Autopilot will Disengage. The most common cause of DFC-90 problems is the connector mating into the old S-Tec 55x Tray. Insure that the unit is securely seated into the rack. …
-
DFC90 Servo Logic SR22 with Pitch/Pitch-Trim
The following is a theory of operation of the pitch/pitch-trim system. The attached drawing will help, and it is advised to opening the drawings while reading through the paragraphs below. The lines highlighted in blue are grounds, and the lines highlighted in yellow are bus voltage (28V). Pitch Down Trim Relay …
-
DFC90/100 Servo Start Up Voltages - Cirrus and Piper
This should be tested using a variable DC power supply, connected as displayed in the image below: Once connected, begin at 0VDC and slowly increase voltage until the servo begins to respond. That will be your "start-up voltage." DFC90 Servo Start Up Voltages Roll Servo should be less than 3VDC Pitch Servo…
