PX200 V5 Manual
13
13/05/2022
12
Voltage Limits
The output voltage range can be restricted to an arbitrary positive and negative value using two
potentiometers on the front panel. To set the voltage limit:
•
Remove loads connected to the outputs
•
Apply a 100-Hz sine wave to the input of channel 1 with an amplitude that covers the full range
of the amplifier. For example, with a 0V to +200V model, apply a 0V to +10V input.
•
Measure the output voltage of channel 1 with an oscilloscope and confirm the full voltage
range is achieved. If there is any clipping of the sine wave, the voltage limits may have already
been set, and may need resetting by winding the potentiometers in the direction of the
arrows.
•
To limit either the negative or the positive voltage, turn the potentiometer in the opposite
direction to the arrow, until the voltage is limited to the desired level.
13
Overload and Shutdown
The amplifier is protected against short-circuit, over-current, and excessive temperature. During
these conditions, the front panel overload indicator will illuminate, and the Shutdown Monitor signal
is +5V.
During an overload or shutdown state, the output is partially disabled and may float at approximately
50% of the voltage range.
When the amplifier is switched on, the overload protection circuit is engaged by default and clears
after three seconds.
The amplifier can be shut down by an external source by applying a voltage of b2V and +24V
to the Shutdown input. The impedance of the shutdown input is approximately 5
kΩ.
14
Bias Outputs and Piezo Benders
The bias outputs are labelled HV+ and HV- on the front-panel screw terminals. The output voltages
are fixed at the maximum output voltages of the amplifier and are not affected by the voltage limit
potentiometers. For example, a PX200-N100-P100 (with a +/-100V output range) will 100V
and -100V on HV+ and HV- respectively. For amplifier configurations where the HV- output is zero
(e.g. PX200-P200), it is preferable to use ground rather than the HV- output.
The bias outputs provide a small DC output current of approximately 30mA; however, they can
source or sink large AC currents, which is ideal for driving piezoelectric actuators. Bender actuators
can be driven with a single or dual bias voltage.
