1: Left: Circuit of Zener Diode Space Flow Detector, showin a 1.5 V AA battery, two 1N4728A Zener diodes operating in revers bias mode, having a Zener voltage
of 3.3 V, and resistor R=10 k[OMEGA] .
In normal operation, the voltage applied to the hazard area is less than the Zener voltage, and the barrier will be virtually transparent to the control loop.
Ideally, Zener diodes would not allow any current in the reverse direction until the Zener voltage has been attained.
Post-experiment analysis starts with retrieval of the runtime calibration data, the stored voltage/velocity data, the stored force/current data, and a file containing the basic reference data: laser wavelength, mass, gravity acceleration, Zener voltage
and drift slope, and resistor value with slope and temperature coefficients.
Measurements made at NIST for the characterization of Zener voltage
standards have enabled the manufacturer to redesign their instruments for improved behavior.
In the following years, after several manufacturers started making commercial Zener voltage standards, these references began to replace standard cells in commercial use.
These two Josephson voltage standard systems are compared every year by measuring a set of Zener voltage standards to check the correctness of JVS operation.
A comparison between a portable BIPM JVS and the NIST-1 V JVS at 1 V was carried out in 1992 with a relative agreement of 1.3 X [10.sup.-8] (k = 2) for an indirect comparison (via mutual measurements of an isolated Zener voltage standard) and 3 X [10.sup.-8] (k = 2) for a direct comparison (78).
For this example, the program checks regulator voltages and then LED and Zener voltages
. A series of digital inputs is applied, and expected output voltages are measured during the DAC test.
(VZ) in this series range from 2.4V to 47V.