Instruction manual

ControlWaveLP Introduction / 1-13
located on the isolated secondary side of the power transformer. The low level detection
circuitry on the secondary side of the power supply monitors the +5V, +12V and -12V dc
supplies. MC* and PFIN* are generated by the sequencer and drive the two optocouplers.
These signals (MC* & PFIN*) are buffered on the secondary side and drive the Status
LEDs located on the FMI/OB Board.
Figure 1-7 - Bottom View of PSSB Board (not all components shown)
The control circuit that drives the watchdog (WD) relay or watchdog (WD) MOSFET switch
is located on the secondary side of the power supply. A solid state relay (U19) is provided to
actuate the WD relay or WD MOSFET switch. The WD relay or WD MOSFET switch can be
disabled by placing PSSB Jumper (JP1) in position 2-3. The WD relay or WD MOSFET
switch is enabled when PSSB Jumper JP1 is set in position 1-2.
An external battery monitor is composed of an ADC and interface circuitry. The ADC is
taken out of shutdown condition when a conversion is started. Interface circuitry consists of
three optocouplers. The conversion and data transfer will take 200usec. The battery input
voltage range is 0V to +30V. When the battery voltage drops below +10.25V or +21.3V, the
circuit will shut down. The accuracy of the reading is ±2% of span.