HP A Series User Manual

cutout in the side panel) may have to be readjusted to
satisfy the above two requirements if the user intends
to operate at an output voltage which is above or below
nominal. For example, if the user has a supply of 10
Volts or above and requires an output voltage of +5%
above nominal, the initial current limit point would be
factory set to approximately 109% of rating. This
violates the 105% current limit constraint mentioned
previously and, thus, the current limit potentiometer
would have to be adjusted (described in Section V) so
that the current limit point is moved to 104 ±1%at
the upper voltage limit rather than at nominal voltage.
A. SUPPLIES BELOW lOV
NOMINAL
OUTPUT
*
* *
3V 89%
119%
4V
93% 115%
5V 95%
113%
6V
97% 111 %
B. SUPPLIES 10V AND ABOVE
CAUTIOM
OPERATION AT OUTPUT CURRENTS ABOVE I0S% OF
RATING CAN CAUSE EXCESSIVE INTERNAL HEATING
AND POSSIBLE DAMAGE TO THE SUPPLY,
3-9 Connecting Load
3-10 Each load should be connected to the proper
supply output terminals using separate pairs of con¬
necting wires. This will minimize mutual coupling
effects between loads and will retain full advantage of
the low output impedance of the power supply. Each
pair of connecting wires should be as short as possible
and twisted or shielded to reduce noise pickup. (If a
shield is used, connect one end to power supply ground
terminal and leave the other end unconnected.)
3-11 if load considerations require that the output
power distribution terminals be remotely located from
the power supply, then the power supply output term¬
inals should be connected to the remote distribution
terminals via a pair of twisted or shielded wires and
each load separately connected to the remote distribu¬
tion terminals. For this case, remote sensing should be
used (Paragraph 3-13).
3-12 Positive or negative voltages can be obtained
from this supply by grounding either one of the out¬
put terminals or one end of the load.
3-13 Remote Sensing (See Figure 3-3)
3-14 Remote sensing is used to maintain good regu¬
lation at the load by reducing the degradation in regu¬
lation that would occur due to the voltage drop in the
leads between the power supply and the load. Remote
sensing is accomplished by utilizing the strapping pat¬
tern shown in Figure 3-3. The power supply should be
turned off before changing strapping patterns. The
leads from the sensing terminals to the load will carry
much less current than the load leads and it is not re¬
quired that these leads be as heavy as the load leads.
However, they must be twisted or shielded to mini¬
mize noise pick-up.
Figure 3-2. Typical Current Limiting Characteristics Figure 3-3, Remote Sensing
3-2

HP A Series Specifications

General

Model	HP A Series
Category	Power Supply
Input Voltage	100-240V AC
Input Frequency	50/60 Hz
Cooling	Fan
Connectors	SATA, Molex
Efficiency	80% or higher (80 Plus Certified)