CyberResearch PCIDIO 48H Benutzerhandbuch

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Operation Theorem 
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4.4  12V and 5V Power Supply   
The OPTO-22 compatible connectors provide external devices the +12 volts 
and +5 volts power supply.  To avoid short or overload of the power supply, 
resetable fuses are added on all the output power.  Refer to Figure 2.5.   
The maximum current for 5 volts on every connector is 0.5 A. If the load 
current is larger than 0.5 A, the resistance of resetable fuse will increase 
because of the rising temperature.  The rising resistance will cause the 
power supply drop and reduce current.  If the overload or short condition is 
removed, the fuse will get to n ormal condition.  It is not necessary to repair 
or re-install the fuse. 
The maximum current of 12 volts for all the four connectors is also 0.5 A.  
The action of the fuse is the same as which used for +5V power.  The 
limitation is more restrictive than 5V  power supply because the PCI bus can 
not provide large current.