Assembly-Level Service
Theory of Operation
2-14
Power Supply Block
The first sentence of the first paragraph at the top of page 3-22 is
changed:
The Power-Supply Block consists of LF1 line filter/cable assembly, T1
toroidal power transformer, A1 rectifier/crowbar/Ext dc input filter
circuits, A11 power steering logic assembly, and A12 Dc-Dc power-
converter module.
The second paragraph at the top of page 3-22 is changed:
The power-supply block provides the instrument with internal dc
power from either an ac power or external dc power source. It
monitors the presence of these power sources, switching from external
dc to ac line as required.
The voltages specified in the third paragraph on page 3-22 are changed:
28 Vrms is 37 Vrms and 32-38 Vdc is 45- 51 Vdc
The fifth paragraph on page 3-22 is deleted:
The sixth paragraph on page 3-22 is changed:
A11 implements the power-source steering hierarchy and provides
power-status signals to A3. A11 receives the dc and ac power sources,
selects one of them and routes it to the A12 Dc-Dc power converter
module.
The last paragraph on page, 3-22 is changed:
A12 converts the 40-58 Vdc steered power to nominal +5V, +12V, and
-12V dc and routes these three voltages to A1 at A1J2.
Option 048:
Option 048:
Option 048:
Option 048:
Option 048:
Option 048: