There are 3 versions of ATE-30 device. All are currently available.
Dave Kornegay was the engineer at Woodward Governor Company
who designed the original PT Interface 25 years ago. The attached
YouTube video introduces a new, improved version of this
hydroelectric turbine speed sensing device.
In 2002, L&S Electric ordered the same PT Interface
contract manufacture from ATECo to Dave's original
specification. Design performance certified to IEC's highest
standards for discriminating customers.
ATE-30 was the first version, still available by special order today.
ATE-31 was an upgrade to meet UL standards with improvements guided by "lessons learned" from the ATE-30 project.
ATE-32 Upgades again to meet the highest IEC standards for a customer.
Addition of a hysteresis
circuit on the input to the isolaton amplfier blocks signals with amplitude less than (+/-)
0.15V. This threshold voltage is adjustable from 0.02 to 1.0V p-p on request.
The subject governors in the video were upgraded to
digital PLC control systems a year ago, but did not replace the 110 VAC voltage wires from the PTs
with instrumentation grade shielded, twisted pair wire, which caused the problem
described in the video. The original purpose of these wires did not
include instrumentation connections of low-voltage signals, so
unshielded wire was OK in the original installation many years earlier. When the PT Interface
input is added to the circuit, the wires changed from "power wiring"
to "instrumentaiton signal wiring" and should be changed to
instrumentation wire. Crosstalk in
the unshileded wiring was measured at
0.14VAC when the other unit was on-line. Threshold voltage of the PT Interface was reset to
0.16VAC. Specification is 0.2 to 180 VAC, with a noise floor at 0.15V.