While a synchro and a resolver are electrically very similar to a transformer, they are S3 mechanically more like a motor. In contrast, as shown in figure 3, a resolver has: Ģ primary windings 2 secondary windings, which are oriented at 90º to each other 2 – Synchro Rotor/Stator Configuration S1 As shown in figure 2, a synchro has: Ģ primary windings 3 secondary windings, with each secondary winding mechanically oriented 120º apartįig. Just like a traditional transformer, they have a primary winding and multiple secondary windings, and just like a transformer, their primary is driven by an AC signal. Theory of Operation Synchros and resolvers are World War II era technology that is still widely used in modern day electronic motion control applications. TO RECEIVER LOOP ANTENNA INPUT INDICATOR MOTOR FROM RECEIVERįig.
110 Wilbur Place, Bohemia, NY 11716įlight surface positioning cockpit simulators jet engine control antenna pedestal control cockpit indicators landing gear positioning and control flap actuators RESOLVER FIXED COIL ROTATING COIL The analog waveforms generated by these transducers, and their characteristics, are detailed in the ARINC407 specification (ARINC Synchro System Manual), but how do synchros and resolvers work specifically? North Atlantic Industries, Inc. As the aircraft turns, the amount of coupling in the transducer changes proportionally as illustrated in figure 1. distance measurement equipment (DME) In an ADF, for example, the resolver or synchro is used to drive an indicator.omni-range system (VOR, very high frequency omni-directional range).inertial navigation reference units (gyro, compass).The simplicity of their connection, combined with today’s modern (and relatively inexpensive) Synchro-toDigital and Digital-to-Synchro converter boards (such as those from North Atlantic Industries) make the synchro a very attractive component. They have traditionally been the transducer of choice where reliability is critical, and where harsh environmental conditions exist.
Synchros & Resolvers Synchros have been used in a wide variety of military and commercial systems for many years. This article will address the systems that utilize these transducers, de-mystify the workings of these AC analog transducers and associated conversion electronics, describe the testing and simulation of these signal types and discuss some common troubleshooting failure mechanisms. Motion Electronics in Avionics Several transducer types, including synchros, resolvers, linear/rotary variable differential transformers (LVDT/RVDT) are key building blocks in flight control and navigation dynamics.