Power Supply - Sun Microsystems SPARCstation 2 Service Manual

1

Power Supply

16
External Storage Module 669 MB hard disk drive only
°
External Storage Module dual 669 MB hard disk drives
°
External Storage Module 669 MB hard disk drive and 150 MB cartridge
°
tape drive
External Storage Module 669 MB hard disk drive and 2.3 GB cartridge
°
tape drive
External Storage Module 2.3 GB cartridge tape drive only
°
These units may be daisy-chained together. By attaching optional
expansion units, you can increase the system's mass storage capacity.
For information on installing and using external drive units, see the
Desktop Storage Pack Installation Guide or the External Storage Module
Installation Guide.
•
Diskette drive
An optional 3 1/2-inch 1.44 MB internal diskette drive (see Figure 1-2) can
be installed in the system unit. The drive accepts a 4-pin AMP power
connector and a 34-pin data cable. The data transfer rate is 1 Mbps (Mbit per
second). "Diskette Drive" in Chapter 4 describes how to remove and
replace the optional diskette drive in the system unit.
The power supply (see Figure 1-2) is housed in the system unit. It connects to
the system via a 12-pin connector and provides +5, +12, and -12 volts DC.
Voltages are regulated. The power supply also supplies the power-on reset
signal.
Some of the power supply's features include the following:
•
Switching power supply
•
Overcurrent protection
•
Crowbar feature
•
Internal fusing
The External drive units have their own power supplies. The External Storage
Module's power supply provides +5, +12, and -12 volts DC. The Desktop
Storage Pack's power supply provides +5 and +12 volts DC.
SPARCstation 2 Field Service Manual—February 1991