In a  message dated 2/6/2016 2:32:45 P.M. Central Standard Time,  

dlk-eng@charter.net writes:

 Mr. B-----:

Doug  Albright asked me to respond to your email about the Model ATE-32.  

I originally designed this circuit, which is one of several versions  that have evolved over a period of approximately 20 years. I designed the first version of PT Interface  for Hydro Quebec for  their LaForge plant to solve a noise problem that  they were  experiencing.  Since then, I have made some improvements to  the  module, including better packaging and much better noise immunity provided by hysteresis in the signal conditioning circuitry.  

Doug Albright's company, Actuation Test Equipment has acted as a contract manufacturing company for me at three of the companies that  I have worked with.  He also markets these modules to end users  and  OEMs.

Doug and I have also worked together since 1985 on the  design of  an automated Index Test Box, which automatically collects  index test data from turbines as they run normally, greatly reducing the labor cost and disturbance to operations of a  conventional index test, which can be the foundation for improving  efficiency (and revenue), reducing cavitation damage, and reducing  fish mortality.

 I have been involved with the  design and  implementation of governor systems since 1971, working with   several different governor OEMs.

This module  is  used as an interface between the 120 VAC instrumentation  Voltage  Transformers (VTs) and the frequency measuring devices used  in the  governor control system, which usually require a 24 volt square  wave.  In addition to changing the voltage level to be  compatible with the frequency measuring module, the ATE-32 module  also prevents electrical noise that may be superimposed upon the VT  voltage from causing erroneous speed measurements.

The output of the ATE-32 module  switches between its high and  low voltage limits as the VT voltage crosses through zero volts.   There is a very slight delay  between the zero crossing of the input  voltage and the change of  state of the output voltage. 

This delay  is approximately  0.1 millisecond, which is insignificant compared to  the update  time of a high-resolution frequency counter (generally 1 or 2 cycles of the VT voltage waveform).  The time duration of each  cycle  of the output voltage waveform from the ATE-32 module is  exactly the same  as the time duration of each cycle of the input  waveform. If you  have any further questions about the operation  of the Model ATE-32 module,  or about governors or index testing in  general, please feel free to contact me.

 Thank you for  your interest.

 David L. Kornegay,  P.E.

DLK Engineering,  LLC