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BOPHV020411
only, to which all input source grounds, shields and load grounds are connected. Multiple
signal grounds in the BOP output/load circuit may cause “ground loop” problems, since
noise signals develop across the impedance between the multiple ground points. The
exact physical location of the “best” single ground must be carefully selected for minimum
ripple/noise output.
F)
EXTERNAL PROGRAMMING RESISTORS. External programming resistors should be
components with low-temperature coefficients. Resistors should be selected carefully,
since in most applications, the limitations for stability and drift are due, not to the BOP, but
to the programming resistors. Selection criteria for resistors are:
1) TEMPERATURE COEFFICIENT
2) LEAKAGE (IN VALUES ABOVE 100k OHM)
3) HUMIDITY EFFECTS
4) DRIFT WITH TIME
5) SELF-HEATING (POWER DISSIPATION)
6) TOLERANCE
G) For variable resistors (potentiometers or rheostats) similar selection criteria apply. In addi-
tion such specifications as listed below should be carefully considered if the application
requires:
1) END RESISTANCE
2) LINEARITY
3) CAPACITIVE AND INDUCTIVE EFFECTS
H) ACTIVE PROGRAMMING SOURCES. External programming sources (Signal Generators,
etc.) or reference sources should have temperature coefficients and drift specifications
comparable to (or better than) the BOP Power Supply.
I)
CAUTION: A-C source operated programming sources must have their output isolated
from the case.
J)
EXTERNAL LEADS. Shielded (preferably twisted) lead pairs are recommended for all
input connections to the BOP control channels. The shield should be connected (single-
ended) to the chosen signal ground point. Shielded leads should be held as short as prac-
ticable. Output leads must be “high-voltage” wire, rated at least for the maximum BOP out-
put voltage and current.
K)
BEFORE USING THE BOP IN ANY APPLICATION....PLEASE REFER TO SECTION 2 TO
GET ACQUAINTED WITH THE OPERATING CONTROLS AND THE A-C POWER
REQUIREMENTS. REFER TO THIS SECTION (SECTION 3) FOR INFORMATION ON
LOAD CONNECTIONS AND GROUNDING. READ THE “WARNING” NOTES PRIOR TO
PAR. 3.1A.
