Nice General Electric 115VAC, 400Hz, 3PH Automatic Pilot Inverter Manufactured for General Electric by the Leland Electric Company of Dayton, Ohio.  This item is also marked as Contract# Noa(s)-5431; Manufactures # 10563-15923.  Date marked on unit is May 31, 1950. This item is a motor – Generator type Inverter.  The input power is 28.5VDC @ 12 Amps.  The output is 115VAC, 400Hz, 3 Phase power 115AV PF= 7% rotation speed= 12,000RPM. The excitation for the generator is 28.5V @ 1.25A.  This information came from the rating plate on the unit.  It measures about 9” L X 5” D X 6” H overall.  It was probably used to power the Gyros / Synchro motors / Electronics in an automatic pilot unit on an early 1950’s Military Aircraft.

 

There is some information that I found on the Internet with regards to this unit:

In the 1950s, automatic pilot systems and onboard electronics in aircraft and ships frequently utilized rotary Motor - Generator (MG) inverters. These electromechanical devices converted DC power (often 28V) into AC power (commonly 115V, 400Hz) required for gyros, synchros, and vacuum tubes. They relied on a DC motor driving an AC generator on a common shaft, serving as the essential power conversion method before solid-state inverters dominated. 

Key Aspects of 1950’s Motor-Generator Inverters:

• Function: Used extensively in aircraft auto-pilots, radar, and navigation systems to convert low-voltage DC to necessary AC voltages.
• Mechanism: Consisted of a DC motor mechanically coupled to an AC generator, often housed together to step up voltage and frequency for sensitive gyro components.
• 1950s Context: While ships began transitioning to AC power, aircraft continued using DC-to-AC MG sets to power specialized electronic equipment.
• Evolution: These devices were rugged and reliable but heavy, preceding the smaller, more efficient solid-state inverters and, much later, inverter generators introduced in the 1980s. 

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These systems were critical for maintaining the stability of early automatic flight controls.

 

This Automatic Pilot Inverter appears to be complete and is in fair – good overall physical and cosmetic condition.

Since we have not tested this item and due to its age (approximately 75+ years old), per eBay protocol I am selling this item for PARTS OR REPAIRS, and as USED, Strictly: AS-IS. The attached pictures form part of the description AND the descriptions are a “BEST EFFORT” on my part so please BID ACCORDINGLY.  This would be a nice item for an aviation museum or for someone who wants to generate 115VAC, 400Hz, 3 Phase power from 28Vdc for testing small aircraft instrumentation.  This item will be well packaged so that it arrives as shown in the pictures. When WELL PACKAGED, the shipping box dimensions are 13” X 10” X 9” and the approximate weight is 10 Lbs. Please note that I am selling this item for PARTS or REPAIRS and as USED, STRICTLY AS-IS.  I ship within 3 days of receipt of funds. Item will ship upon receipt of guaranteed funds.