Calibration, Calibrating for readback accuracy, 4 calibrating for readback accuracy -4 – American Magnetics 12200PS DC Power Supply (CE-Marked) User Manual
Page 53: Calibration 5.1 introduction, 2 calibration setup
OPERATING MANUAL
CALIBRATION
Release 1.0 (98/07)
5-1
5. CALIBRATION
5.1 Introduction
HIGH ENERGY/HIGH VOLTAGE WARNINGS
Exercise caution when using and servicing a power supply. High energy
levels can be stored at the output voltage terminals on a power supply in
normal operation. In addition, potentially lethal voltages exist in the power
circuit and on the output and sense connectors of a power supply with a
rated output greater than 40V. Filter capacitors store potentially dangerous
energy for some time after power is removed.
Adjustments to programming and readback accuracy for the power supply are made using cover-off procedures
which must be performed by a service technician.
5.2 Calibration
Setup
5.2.1
Service Environment and Precautions
•
Follow established antistatic procedures.
•
Work at a bench with adequate room and support for the unit under test and for all equipment required.
•
To reduce shock hazard, use only an insulated, straight-blade screwdriver when calibrating trim
potentiometers.
•
NEVER calibrate these units alone. Ensure that someone is present who can help should an accident
occur.
5.2.2
Equipment Required
You will need the following equipment when calibrating your power supply.
•
5 1/2 digit true RMS voltmeters (DVMs) (±0.05% accuracy) with test leads
•
Current shunt 1mV/AMP (±0.25%) and connecting wire. The recommended current ratings for the DC
shunt and connecting wire must be at least 10% greater than the power supply's output current rating.
See also Table 5.2-1.
•
Non-conducting, straight-blade screwdriver
Table 5.2-1 Current Carrying Capacity for Wiring
Wire Size (AWG)
Maximum Current (A)
Wire Size (AWG)
Maximum Current (A)
20
2.5
6
61
18
4
4
97
16
6
2
155
14
10
1
192
12
16
1/0
247
10
21
2/0
303
8
36