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LEAD IMPEDANCE AND LOCAL DECOUPLING
It is important that local decoupling be used a,. the load if
long leads are used due to the high impedance of the leads at high
frequencies. For very long leads a heavy, shielded, twisted pair
type of cable should be utilized. . 0 lpf ceramic capacitors across
the output leads at the load are also recommended.
NEGATIVE CURRENT LOADING
The supply is not built to regulate when current is pumped
into the output of the supply from an external source. If it is
necessary to operate in this manner, then a resistor must be used
to load the output terminals of the supply by an amount equal to the
maximum instantaneous current pumped into the supply.
MAINTENANCE
MEASURING THE PERFORMANCE OF THE SUPPLY
. ?When measuring the output impedance, transient response, or ripple
of the supply, be sure the measuring device (differential voltmeter, digital voltmeter
or oscilloscope) is attached to the sensing leads of the supply. It is important that
none of the output current flows through the lead lengths in series with the monitoring
device since such lead lengths can easily have an impedance of the same order of
magnitude as the supply impedance and thus effectively make the measurement invalid .
When measuring the power supply ripple, connect either the positive or negative
terminal of the supply to the chassis ground, and the scope case to the same point
making certain that the scope case is not also grounded by some other means (such
as a three wire power cord). To be doubly certain that the scope is not exhibiting
a ripple or transient spike that actually is not coming from the power supply, connect
both scope leads simultaneously to the power supply ground terminal. No ripple or
transient spike should be visible if the power supply is properly connected to the
scope .
The only maintenance required of this supply is that it be kept
reasonably clean and free of dust and metallic particles. |
ACEC
