Specifications

Voltage Programming With an External Signal Source
Question: Can Agilent power supplies be programmed from 0 to full output voltage using a 0 to 10V signal source?
Answer: 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 isolated 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 output 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 programmed 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.
Refer to the topic on Constant Voltage Programming with Variable Voltage Gain in the application section of the
Power Products Catalog for more detailed information.