Sandia Aerospace ST 32 - Manual (Page 5)

1.3.3.3 Tach Input Requirements
The ST 32 requires the following input from the on-board strain gauge pressure transducer:
Exitation Voltage: 9.0 Vdc-10.5Vdc
Signal Voltage:
Common Mode: 2Vdc to Aircraft Voltage -2Vdc
Differential Mode: 0mVdc - 100mVdc
1.3.3.4 Approved strain gauge pressure transducers are:
Kulite APT-20-1000 or Equivalent
1.3.3.5 The ST 32 digital output signal is:
Totem Pole outputs to Aircraft Power
Rise time: 5 usec
Fall time: 5 usec
Low voltage: < 1.9 Vdc
High Voltage: Aircraft Power
Voltage to Frequency Conversions
Signal Conversion:
Input Output Accuracy
0 mVdc 20KHz 0.1% Full Scale
100mVdc 100KHz 0.1% Full Scale
Excitation Conversion:
Input Output Accuracy
9.0 Vdc 20KHz 0.1% Full Scale
10.5Vdc 100KHz 0.2% Full Scale
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