Le labo de Michel | LDM #368: Sperry AD-300C Attitude Director Indicator - Teardown and test @lelabodemichel5162 | Uploaded 3 months ago | Updated 2 hours ago
This video shows the teardown and test of an Attitude Director Indicator model AD-300C manufactured by Sperry.

00:00 - Intro
00:56 - Teardown
02:25 - No gear train
02:50 - Test
05:53 - Attitude circuits modular circuit

Notes:
* This ADI uses a DC motor for the roll control and a torque motor for the roll
* There is no gear train, the motors are directly linked to the gimbal for the roll and to the sphere for the pitch. This permits to save some weight and cost, the counterpart is the lack of stability when quick change of pitch or roll accurs. However this shouldn't be a problem with commercial aircraft.
* The electronics use mainly potted modules

Pinout:
26-27-28: roll synchro input
29-30-31: pitch synchro input
10: 28V attitude enable signal (from vertical gyro)