Th-e California Instruments’ Model 848TCM AC Power
Controller is designed as a plug-in controller of frequency
and waveform amplitude. The 848TCM will plug into and obtain
power from all California Instruments AC Power Sources. The
frequency and amplitude are locally controllable by a front
panel keyboard or remotely programmable by the IEEE-488
Option PC for the associated power source is required to
mount the IEEE-488 interface connector in its rear panel.
The output of the Model 848TCM provides three-phase variable
frequency and amplitude drive for the power source, The
remote sense input monitors the voltage across the load. The
voltage at the sense point will be maintained by the Model
848TCM to be equal to the programmed value. In the event
that this voltage cannot be maintained, the Model 848TCM
will automatically set the output voltage to zero volts and
then step the output voltage in five volt increments to the
programmed value. If the programmed voltage is still not
maintainable, the Model 848TCM will set the programmed
voltage to zero volts and display an error message
coincident with the phase or phases generating the fault.
The Model 848TCM employs digital techniques for control of
the output frequency.
A crystal controlled oscillator serves as the clock for the
digital frequency generator that controls the output frequency.
This circuit configuration provides the same long-term
frequency stability as the crystal time base. The crystal
time- base is adjusted at the factory for a frequency
accuracy of ±5 ppm.
The output frequency will, therefore, be equal to ±5 ppm of
the programmed frequency*
The Model 848TCM is capable of operating from 45 Hz to 9999
Hz, 999.9 Hz or 99.99 Hz in 1 Hz, .1 Hz or .01 Hz steps
depending on the frequency range (see paragraph 1.3). The
low end of the frequency range is limited by a frequency
detector to 45 Hz. The high end is factory adjusted to the
upper full power frequency limit of the associated power
source. If an attempt is made to program the frequency
outside these frequency limits the amplitude will default to
zero volts and the display will show the error message E 71.
The Model 848TCM must be used on the 135 volt range when
used with a power source on the 120, 130 or 135 volt range.
It must be on the 2 70 volt range when used with a power
source on the 240, 260 or 270 volt range.