Safety Precautions; Maintenance And Calibration - Elenco Electronics XP-660 Instruction Manual

Safety Precautions

Certain safety procedures must be observed when
this power supply is used with external circuits that
are connected to AC power lines. There is always
some danger when working with electrical
equipment or circuits that operate at hazardous
voltages. You should thoroughly familiarize yourself
with the equipment before working on it.
voltage may appear at unexpected points in
defective equipment.
The Elenco ® power supplies are equipped with three
wire line cords which ground the chassis to power
line cord. DO NOT CUT OFF OR DISABLE THE
GROUND PLUG.
The power supply secondary circuits are isolated
from the 120V primary circuit via the power
transformer. When working with other equipment, this
may not always be the case. Always be familiar with
the equipment rating. Keep in mind that defective
equipment can have dangerous voltages at
unexpected points. CAUTION: When removing the
cover for fuse replacement, always disconnect the
power cord from the AC socket. Service repair should
only be done by qualified personnel who are
knowledgeable of electrical hazards.

Maintenance and Calibration

The Elenco ® Models XP-660 and XP-760 have been
designed and manufactured to require no routine
maintenance. The circuits are protected by design
from external shorts or overloads.
information is provided in the event the supply requires
service or re-calibration.
Fixed 5VDC Regulation Calibration
1) Connect an accurate digital meter to the output
of the 5V supply.
2) Adjust the variable resistor VR101 to read
5.0VDC.
Variable 0-20VDC Regulator
Calibration
1) Connect an accurate digital meter to the output
2) Set the voltage pot to maximum position.
3) Adjust the variable resistor VR302 of Power One
High
Digital Meter Calibration
for Model XP-760
1) Note the small pot (R2) on the top of each
2) To set the accuracy of the meter you need
3) To set the accuracy of the current measurement
The following
-5-
of the 0-20V supply.
Supply for 20.0V. Adjust VR203 for Power Two
Supply.
meter's PC board. This is the GAIN pot which
controls the accuracy of the meter.
another very accurate digital meter. Connect
this meter to measure the voltage on the output
terminals of the supply under adjustment. Set
the output to 18VDC. Set the Volts/Amps switch
to Volts and adjust the GAIN pot for 18.0 on the
XP-760 meter.
connect a suitable load to the output and
connect the accurate digital meter to measure
the current in the load.
switch to Amps. Set the output current to 0.8
amps. Adjust VR304 (Power One Supply) or
VR204 (Power Two Supply) for a reading of 0.8
on the XP-760 meter.
Set the Volts/Amps