Envision Peripherals NV3128 - Manual (Page 72)

NV3128 RS-422A Machine-Control Data Routing Switch 4-10
4.2.5 POWER SUPPLY ASSY: PS2001-XX
The NV3128 Frame and its Power Supply are UL listed. The Power
Supply Module PS2001-01 powers the NV3128 from the AC line at
a nominal voltage of 115 VAC - 60 Hz or 230 VAC - 50Hz. The power
supply is designed to accept input voltages in the range of 88 VAC to
135 VAC, or 210 VAC to 270 VAC and to provide DC outputs of
+17V, -17V, +7V, and -7V.
AC Power enters the system through connectors mounted on the rear
panel. In addition to providing an AC connection, each connector
contains both a 1.6 ampere fuse and a Radio Frequency Interference
(RFI) /Electromagnetic Interference (EMI) filter.
This bi-directional filter attenuates noise on the power line and noise
generated by the power supply to acceptable maximum limits set by
FCC and VDE guidelines. A spare fuse, accessible at the rear of the
frame, is included inside the power entry module.
A single PS2001 can safely supply the NV3128. A second may be
added for redundancy.
CAUTION: HIGH VOLTAGES EXIST IN THE INPUT AND RECTIFIER
CIRCUITRY. ALWAYS USE CAUTION WHEN HANDLING
COMPONENTS IN THESE DANGEROUS AREAS.
The AC input voltage is rectified by diodes and filtered by capacitors.
This provides raw DC at a high voltage.
CAUTION: THE SETTING OF J1 SHOULD BE PERFORMED BY
QUALIFIED SERVICE PERSONNEL ONLY.
The power input source and jumper location must be consistent.
Jumper J1 is set at the factory for either 115 VAC or 230VAC.
ALWAYS CHECK FOR THE CORRECT SETTING BEFORE
APPLYING POWER TO THE UNIT IN A NEW INSTALLATION.
When the jumper is in the 115 VAC position, the input circuit acts as
a voltage doubler. The raw DC output is the sum of the positive and
negative half-cycle peak voltages. When the jumper is in the 230 VAC
position, the AC input is rectified by the full-bridge diode circuit. Both
configurations produce the same nominal 230 VDC raw output voltage.
The power supply module incorporates several protective elements. A
common problem with off-the-line switching power supplies is a high
peak in-rush current due to low input impedance. A thermistor
mitigates this problem by presenting a high startup resistance. As the
capacitors start to charge, current flowing in the circuit warms the
device dropping the resistance and minimizing its effect on the circuit.