Overall Description; A18 Cpu; A19 Power Supply - Keysight Technologies E8257D Service Manual

Troubleshooting

Overall Description

Overall Description
The overall description provides a functional overview of the Keysight PSG
signal generators. Some of the functional blocks discussed are common to
many types of instruments, while others are more specific to analog and vector
signal generators.
Common functions:

— A18 CPU

— A19 Power Supply

— Input/Output Interface
Specific signal generator functions:
— Frequency Generation
— Output Power Level/Automatic Leveling Control
— Analog Modulation (Option UNU Standard Pulse, UNW Fast Pulse, UNT
A18 CPU
The A18 CPU controls all activities in the signal generator:
— translating information entered from the front panel keys, LAN, GPIB, or
— communicating translated instructions on the internal buses
— monitoring critical circuits for problems, such as unleveled and unlocked
— reporting (on the front panel display) any problems with critical circuits
A19 Power Supply
The power supply has an internal line fuse that cannot be replaced. If the fuse
opens, the power supply must be replaced.
Voltages
The main power supply converts line voltage (120 Vac or 240 Vac) to regulated
dc voltages. Some of the required dc voltages are not directly available from
the main power supply and are provided by re–regulating one of the main
power supply voltages to the required voltage. This regulation can take place
on any assembly and then routed to the required assemblies.
134
AM/FM and Phase Modulation) and Digital Modulation
Auxiliary Interface (RS–232) into machine–level instructions
conditions
E8257D/67D, E8663D PSG Signal Generators Service Guide