Farnell TSV 70 - Setting Up Procedure; Accessing Internal Components; Voltage Range and Current Limit Setup; Meter Calibration

ACCESS.
Access to the circuitry may be gained by first removing
the rear panel, and then withdrawing all the covers, bottom
two sides and top, which are located in slots in the four
extruded bar chassis members.
1)
Setting the Voltage Ranges, and Current Limit.
2)
3)
4)
5)
6)
SECTION_V
SETTING UP PROCEDURE.
1)
2)
3)
Set the "RANGE" Switch to 35V, 10A. Set the COARSE
and FINE front panel controls to fully clockwise.
Apply mains input to the unit and adjust T2 on circuit
board No. 1 to give 35.5 volts output.
With the CURRENT LIMIT control set fully anti clockwise,
and a short circuit applied to the output terminals,
adjust T3 circuit board No. 1 to give zero output
current. Remove the short circuit.
Connect a load to the output terminals and adjust it
to
give
11
Amps
output
current,
with
the
"CURRENT
LIMIT" control fully clockwise. Adjust T4 circuit
board NO. 1 until the output voltage of the unit just
begins
to
fall
at
11
Amps.
Disconnect
the
load.
Circuit board No. 1 is located on the right hand side
of the unit viewed from the front, and is the .circuit board
nearest to the front panel.
Set the range switch to 70v,; 5A. Set the COARSE and
FINE voltage control fully clockwise.
Setting
the
meter
fu1l
scale
deflections.
Adjust Tl circuit board No. 1 to give 71 volts output.
With the RANGE Switch on the 70V 5A position adjust
the output voltage of the unit by means of the COARSE
and FINE front panel controls togive 70 volts output,
as indicated on an accurate external meter. Set Tl01
until the front panel voltmeter reads 70 volts (full
scale)
With the RANGE Switch on the 35V lOA position adjust
the output voltage of the unit to give 35 volts as
indicated on an accurate external meter. Set T102
until the front panel voltmeter reads 35 volts. (full
scale).
With the RANGE Switch on the 35V 1OA position apply
an accurate external ammeter across the output terminals.
Adjust the CURRENT LIMIT Control to give a reading of
10 amps on this external meter. Set Tl04 until the
- 8
front panel amneter reads 10 amps (full scale).