32
Theory of Operation
The Main Power Supply Assembly
The Main Power Supply Assembly
The main power supply (MPS) comprises a closed assembly (no onsite repair
possibility).
The power supply provides all DC voltages used in the spectrophotometer
except for the voltages supplied by the lamp power supply to the deuterium
and tungsten lamps.
Figure 5 Main Power Supply (MPS) Block Diagram
WARNING To disconnect the instrument from line, pull out the power cord. The
power supply still uses some power, even if the power switch on the
front panel is turned off.
No accessible hardware fuse is needed because the main power supply is
safe against any shortages or overload conditions on the output lines. When
overload conditions occur, the power supply turns off all output voltages.
+36V
supply
+24V
supply
+ 5V
sw itching
re g u la to r
linear voltage
re g u la to rs
+36V (not used)
+24V / 4.5A
+5V / 3A
+ 1 5 V / .3 A
-1 5 V / .3 A
lin e
voltage
prim ary
circ u its
MPS
sense