BEHLMAN BL10000 Series, Руководство пользователя и техническое руководство

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Theory of operation (continued)
5.5.4 The output amplitude of each phase is also regulated by the phase control card. A sample of the output
voltage is fed to an RMS to DC convertor (U4). The resultant DC voltage is compared to a reference DC voltage
set by the front panel voltage control or remote interface. This comparison is performed by U3a and is
integrated to provide an error signal to control the amplitude of the sine-wave signal fed to the PWM modulator.
Compensation for load line (wire) drops performed by summing in a signal form the current monitor. The more
current drawn, the more correction is provided. This compensation is adjustable via the front panel.
5.6 METERING
5.6.1 Metering is provided by DC signals taken from the phase control cards. These signals are derived from
the voltage and current monitoring circuits. These signals are attenuated and applied to the front panel DVM's.
The frequency display derives it's data from the VCO signal.
5.7 MISCELLANEOUS
5.7.1 Internal heat-sink temperature is monitored via a sensor mounted to the extrusion. The sensor is
normally open but will close when a safe temperature is exceeded. When this sensor closes the PWM signal
is eliminated by setting the same latch used by the short circuit protection.
5.7.2 The optional GPIB board provides an isolated computer interface for remote control of frequency,
voltage, and the output relay. The GPIB card will also provide read-back of current and voltage to the GPIB.