User guide

14797 • November 2004 • Power Supply Module (PS5000)

Page 15

POWER SUPPLY MODULE (PS5000)

The Power Supply module accepts and adjusts automatically to a wide range of AC

input voltages (90-130/180-250 VAC, 50/60 Hz). Regulators on the module rectify the

AC to produce +/- 7 and +/- 15 VDC which is distributed to the other modules in the

frame.

Figure 11 shows a block diagram of the Power Supply module. The input stage of the

supply includes an AC power line fuse to protect the equipment and a Power Factor

Correction (PFC) stage, which minimizes harmonics and peak currents on the line.

Following this stage a Switching Regulator produces the required DC voltages. Sharing

diodes on the DC rails allow redundant supplies to connect in parallel with isolation

between the supplies. Power for the cooling fan and the green “power on” indicator

LED comes from the +15 volt rail.

Key features of the power supply are the following:

• Power factor correction

• Auto-ranging; no input voltage selection required

• Fused input

• LED DC power present indicator

• Current, voltage, and power limiting

• Charge dump circuit drains hazardous voltages when the power supply is removed

from the frame.

Figure 11. Power Supply Block Diagram

Fuse and

Filter

Power Factor

Correction

Switching

Regulator

Control

Circuits

Voltage, current, and

power sensing and

limiting

-7

+15

-15