HP 6259B User Manual

3-14 When adjusting the crowbar trip point, the
possibility of false tripping must be considered. If the trip
voltage is set too close to the supply's operating voltage,
a transient in the output would falsely trip the crowbar.
For this reason it is recommended that the crowbar be set
higher than the output voltage by 5% of the output voltage
plus 2 volts for the Models 6259B, 6260B, or 6261 B, or
5% of the output voltage plus one volt for the Models 6268B
or 6269B. If an occasional tripping of the crowbar can be
tolerated as a load is being disconnected, the crowbar trip
point can be set much closer to the operating voltage of
the supply.
3-15 Connecting The Load
3-16 To satisfy the requirements of safety, the wires to
the load should be at least heavy enough not to overheat
while carrying the power supply current that would flow if
the load were shorted. Generally, heavier wire than this is
required to obtain good regulation at the load. If the load
regulation is critical, use remote voltage sensing. (Refer to
paragraph 3-27.)
3-1 7 If multiple loads are connected to one supply,
each load should be connected to the supply's output
terminals using separate pairs of connecting wires. This
minimizes mutual coupling effects between loads and takes
full advantage of the supply's low output impedance. Each
pair of connecting wires should be as short as possible and
twisted or shielded to reduce noise pickup.
3-18 If load considerations require the use of output
distribution terminals that are located remotely from the
supply, then the power supply output terminals should
be connected to the remote distribution terminals by a
pair of twisted or shielded wires and each load should be
separately connected to the remote distribution terminals.
Remote voltage sensing would be required under these
circumstances. (Refer to paragraph 3-27.)
3-1 9 Either positive or negative voltages can be obtained
from this supply by grounding one of the output terminals
or one end of the load. Always use two wires to connect
the load to the supply regardless of where or how the
system is grounded. Never ground the system at more than
one point. This supply can be operated up to 300 volts
above ground if neither output terminal is grounded.
3-20 Operation With No Load
3-21 When the supply is operated without a load, its
down-programming speed is considerably slower than when
its output is loaded. This slower programming speed is
evident whether the VOLTAGE controls are turned fully
counterclockwise or an external voltage programming input
signal is decreased. When the crowbar is activated during
no-load operation, the supply's output falls rapidly to about
two volts and then decreases more slowly towards zero.
The actual time required for the output to fall from two
volts to zero varies from several seconds to several minutes,
depending on the output rating of the supply.
3-22 Operation Beyond Rated Output
3-23 The supply may be able to provide voltages and
currents greater than its rated maximum outputs. Operation
can extend into the shaded areas on the meter face without
damage to the supply, but performance cannot be guaranteed
to meet all specifications.
3-24 OPTIONAL OPERATING MODES
3-25 The optional operating modes discussed in the
following paragraphs include:
a. Remote voltage sensing
b. Remote programming
c. Auto-Parallel operation
d. Auto-Series operation
e. Auto-Tracking operation
Special operating instructions for instruments equipped
with Option 040 to permit their interfacing with a Model
6940B Multiprogrammer or a 6941 B Multiprogrammer
Extender are not included but can be found in the manual
covering the programmable resistance cards that are neces¬
sary to complete the interface. Special calibration instruc¬
tions for power supplies equipped with Option 040 are
included in Section V of this manual.
3-26 By changing its rear panel strapping pattern
according to the instructions which follow, any of the
supplies covered by this manual can be operated in any
of the modes listed above.
-CAUTION-
Disconnect input ac power before changing any
rear panel connections and make certain all wires
and straps are properly connected and terminal
strip screws are securely tightened before
reapplying power.
3-27 Remote Voltage Sensing
3-28 Because of the unavoidable voltage drop developed
in the load leads, the normal strapping pattern shown in
Figure 3-2 will not provide the best possible voltage regula¬
tion at the load. If, for example, one were to use 4-gauge
wire to connect a load that is located only 5 feet from a
3-3

HP 6259B Specifications

General

Brand	HP
Model	6259B
Category	Power Supply
Language	English