5
AMI
EXCELLENCE IN MAGNETICS AND CRYOGENICS
6. Install an instrumentation cable between the LHe/Temp connectors J8A and/or
J8B on the rear of the Model 420 and the Model 13x Liquid Helium Level
Instrument and/or temperature instrument (9).
7. Remote communications via IEEE-488 and/or RS-232 (or optional RS-422) can be
accomplished by connecting suitable cabling to J11 and/or J12 of the Model 420,
respectively.
IV. OPERATION
A. During normal operation of the Model 4Q05100PS, no operator intervention is
required.
B. The Model 4Q05100PS is operating if the
32:(5
switch is in the ON (
,
) position. The
output voltage may be monitored via the
9
V
display (commanded supply voltage) of the
Model 420.
C. Control of the Model 4Q05100PS is achieved by using the AMI Model 420 Power
Supply Programmer ramping functions.
The Model 4Q05100PS
352*5$0,1
is a
−
10 to +10 VDC input, which controls the
output voltage of the unit using a gain factor of 0.5.
WARNING: Exercise caution near the supply output terminals on the
rear of the unit when operating a magnet. Metallic objects shorted
across the terminals may conduct large DC currents which are capable
of melting the object and causing severe burns.
D. The
287387,1+,%,7
switch functions as an emergency override. The output of the
Model 4Q05100PS is forced to zero volts by activating the switch. If the switch is
deactivated, the
352*5$0,1
signal controls the output voltage of the Model
4Q05100PS.
Turning off the AC mains is not recommended during non-persistent magnet operation
since the overvoltage protection of the Model 4Q05100PS will activate and discharge
the magnet at ±6 VDC. The
287387,1+,%,7
switch is the preferred alternative in
the event of a system malfunction.
NOTE: Once the
287387,1+,%,7
switch has been activated, the
Model 420 will no longer have control of the magnet system current.
Before attempting to recharge the magnet, cycle the Model 420 power (to
