Power Supply Assembly
- The following describes an obsolete procedure or component.
The Power-Supply Assembly (PSA), or Power-Supply Unit (PSU), is an obsolete power conditioner for the MCE. It took ±150VDC generated by the AC-DC Unit (ACDCU) and produced Vcore, Vlvd, Va+, Va-, and Vah needed to power the cards in the subrack, output on the standard Winchester power connector. (See MCE Power for details.)
The PSA was monitored and controlled through a digital controller, the Power-Supply Unit Controller (PSUC). The PSUC communicated with the Clock card, and could be controlled through the obsolete psu MCE command target. See also the obsolete psc_status.
Technically, the Power-Supply Assembly (PSA) refers to the combination of a power-supply unit (PSU), which does the power conditioning, and the digital PSUC which operates it. These two parts are housed in a box (the PSA) designed to be mounted in a 72HP subrack, next to the clock card. The smaller 48HP subrack does not have space for the PSA, and it must be run externally.
In practice, the terms "power-supply assembly" (PSA) and "power-supply unit" (PSU) are used interchangeably to refer to the PSA as a whole.
Legacy documents
The low-level Clock card-PSUC communication protocol is described in the following, obsolete document:
