AR 10037990, Operating And Service Manual, Page: 26 / 54

Model 250T6G18
6 Rev A
2.3 DESCRIPTION OF THE POWER SUPPLY
The TWT power supply is of modular construction. Low voltage power for logic and control of the entire power
supply assembly, the preamplifier, and the HPA interface board is provided by the low voltage power supply
module (A23687-001). Control logic and TWT protection circuits are contained in the HPA logic and Control
Assembly (A16485-000).
The Heater Power Supply Module (A10010-000) powers the TWT DC heater. Bias and pulse top voltage for the
TWT grid are provided by the Modulator Assembly (A23684-121).
The high voltage power supply consists of the following: the Power Factor Correction module (A23683-000)
converts line voltage to DC for the high voltage switching supply. Switching is controlled by the Pulse Width
Modulation (PWM) Board (A10017-500). The high voltage transformer and rectifiers are contained in the High
Voltage Diode/Cap Assembly (A22818-002). The high voltage DC is filtered in the HV Filter Assembly
(A21461-000).
Interconnects between the power supply modules are through a motherboard. It is installed in a finned heat sink
assembly to which the modules are bolted. The heat sink is cooled by the incoming cabinet air. The Heat
Sink/Motherboard assembly is A24357-000.