Product specifications

126
Power Products 10 Most frequently asked questions about using
Applications Information DC power products
(Continued)
More detailed specifications at www.agilent.com/find/power
10
Can Agilent power supplies be
programmed from 0 to full output
voltage using a 0 to 10 V signal
source?
Yes, many Agilent power supplies
feature remote voltage programming
or analog programming capability.
However, there is a potential danger
in analog programming any power
supply, especially a high voltage
supply. If the 0 to 10 V programming
source is a typical, non-isolated,
low-cost, digital-to-analog converter
(DAC), it is probably grounded
through its digital inputs and/or
through the computer’s internal
power supplies, which are grounded
through the computer’s power cord.
It’s easy to overlook this, and the
mistake can be very expensive.
If the DAC is non-isolated (or iso-
lated only up to 42 V above ground)
and one of the output terminals of
the power supply is grounded, either
directly or through the UUT, the out-
put capacitor of the power supply
can discharge through the computer
backplane, motherboard, and the
I/O common through the computer
power cord ground. The resulting
high current may even last long
enough to vaporize the thin ground
tracks on some or all of the printed
circuit boards in the PC.
Be sure the programming source
is electrically isolated, is operated
from isolated power supplies, and
is rated for floating voltages up to
the full output voltage of the pro-
grammed supply. This is necessary
so no one is hurt, and no equipment
is damaged, no matter which output
terminal of the power supply or
UUT is grounded.
For additional questions and
answers visit our web site
at www.agilent.com/find/answers