© Bartington Instruments Page 4 of 17 OM3225/3
Safe Use
WARNING: The PA1 Power Amplifier is powered by mains electricity and contains
uninsulated parts. Ensure that the unit is properly earthed at all times. Do not open the
casing or have contact with any internal parts except where following a procedure precisely
as described in this manual. Safety protection will be impaired if the unit is used in a
manner not specified in this manual.
WARNING: The electromagnetic field from this product may interfere with the operation
of pacemakers and other medical devices. Consult your device’s manufacturer before
operation.
WARNING: These products are not qualified for use in explosive atmospheres or life
support systems. Consult Bartington Instruments for advice.
WARNING: Personal injury may result from lifting the PA1 Power Amplifier. Use more than
one person to move this device. It should be carried by each of the four lower corners.
CAUTION: When operated at full power for extended periods of time, thermal cut-out may
be activated to protect the equipment from overheating. Should this occur, the power to the
PA1 will be cut. In such event, it is advised to allow the unit to cool down before restarting
it. To prevent the thermal cut-out from activating, the equipment should be used in a
cooled temperature controlled environment (refer to Section 4.6)
Introduction
The PA1 Power Amplifier is the power amplifier for our Helmholtz Coil System. It delivers power
to the coil so as to generate the appropriate the required field. Additionally a permanent DC
offset can be applied to the Helmholtz Coils via the PA1 front panel DC offset potentiometers.
The following items allow to consitute a complete Helmholtz Coil System:
• HC1, HC2, HC9 or HC16 Helmholtz Coils: an assembly of up to three Helmholtz coils. See
related operation manuals.
• PA1 Power Amplifier.
• CU1 Control Unit: the control unit for the system which enables it to interface with a PC-
based test, measurement and control system. See OM3224.
• Optional CU2 Closed-Loop Module: allows active cancellation of external DC and AC
magnetic field disturbances using the CU2 Reference Magnetometer. See OM3999.
• A National Instrument acquisition card or PXI system.