ADLINK PCI-8554 - Manual (Page 34)

24 • Getting Started
2.16 12V and 5V Power Supply
The 100-pin SCSI-II connector provides +12 and +5 volt power sources.
To avoid shorts or overloads of the power sources, thermistors are added
to all power supply rails. The current rating of the +5 volt supply thermistor
is 500 mA. If the load current is larger than 500mA, the resistance of the
thermistors will increase due to the temperature rise. The rising resistance
drops the supply voltage and hence reduces the current. If the overload or
short condition is cleared, the thermistor will return to normal operation.
The +12V supply thermistor also has the same current rating
characteristics as the +5V supply.