SCR Power Control Systems

Digital AutoSync Module

The all new and unique Zeefax Digital AutoSync module benefits from modern advances in manufacturing and control technologies.

In response to many customer requests, we have designed our own version of the legacy Ross Hill Controls AutoSync AC generator control module; the new module has been completely re-designed and incorporates all new digital circuitry as well as optional expansion capability to future proof the module.

The new Digital AutoSync is not available from any other supplier in the world.

The use of modern digital circuitry and components has resulted in much improved parameter control over the previous legacy module without compromising operational reliability, and the ultra-stable frequency control system ensures safe and accurate control of generation systems.

The new front panel includes the familiar controls, but has been enhanced with the inclusion of an LCD display for module set-up and parameter display purposes; front panel controls include the manual circuit breaker and engine controls, with the addition of digital menu navigation buttons for module set-up and display options.


  • Completely redesigned and modernized
    • All new digital AC / AutoSync motor control module
  • Fully compatible with the now obsolete AC III module from Hill Graham Controls (HGC)
    • Can be retro-fitted directly with minimum changes to the existing control system
  • New Metering Functions
  • Hands-off-Cranking (H.O.C.)


The AC Regulator module associated with each generator section typically has four basic main functions:-

  • The exciter function
    • This controls the voltage and KVAR of the generator
  • The governor control function
    • This controls the speed and kilowatt output of the engine
  • The protection circuits for the engine and generator
  • The control and indicator function