Difference between revisions of "H742 Power Supply"

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The '''H742 Power Supply''' is a modular [[power supply]] system from [[Digital Equipment Corporation|DEC]], used in [[PDP-11/40]], [[PDP-11/45]] and [[PDP-11/70]] systems mounted in a [[BA11-F Mounting Box]].
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The '''H742 Power Supply''' is a modular [[power supply]] system from [[Digital Equipment Corporation|DEC]], used with the [[BA11-F Mounting Box]]; among other uses, this mounting box is used in
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[[PDP-11/40]], [[PDP-11/45]] and [[PDP-11/70]] systems to hold the [[Central Processing Unit|CPU]].
  
It runs off standard wall [[Alternating current|AC]]; it can be [[jumper]]ed to use either 110V or 220V supply.
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The H742 runs off standard wall [[Alternating current|AC]]; it can be [[jumper]]ed to use either 110V or 220V supply.
  
The H742 supplies a modest amount of +15V [[Direct current|DC]] power to various [[backplane]]s mounted in the BA11-F, along with a [[line time clock]] signal, and AC and DC 'power OK' signals.
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The main [[transformer]] in the H742 provides 20-30V AC to several [[DEC standard modular regulators]] (up to five, in spaces numbered 'A' through 'E') mounted in the H742, which provide other voltages such as +5V to the [[backplane]]s in the mounting box.
  
It also supplies 20-30V AC to several [[DEC standard modular regulators]] (up to five, in spaces numbered 'A' through 'E') mounted in the H742, which provide other voltages such as +5V to the backplanes in the mounting box.
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Generally the [[power harness]] supports only limited options as to which regulator can be in which spaces; e.g. the later -11/40 harness mandates that A, B and C hold [[H744 +5V Regulator]]s, D holds an [[H745 -15V Regulator]], and E may hold either an H745 or [[H754 +20V, -5V Regulator]].
  
Generally the [[power harness]] supports only limited options as to which regulator can be in which spaces; e.g. the later -11/40 harness mandates that A, B and C hold [[H744 +5V Regulator]]s, D holds an [[H745 -15V Regulator]], and E may hold either an H745 or [[H754 +20V, -5V Regulator]].
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A 5409730 board in the H742 supplies a modest amount of +15V [[Direct current|DC]] power to various backplanes mounted in the BA11-F, along with a [[line time clock]] signal, and AC and DC 'power OK' signals.
  
 
The harness used [[DEC power distribution connectors]] to provide power to the backplanes; it normally used the [[DEC standard power wire colour coding]].
 
The harness used [[DEC power distribution connectors]] to provide power to the backplanes; it normally used the [[DEC standard power wire colour coding]].
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==See also==
 
==See also==
  
* [[H765 Power System ]]
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* [[H765 Power System]]
  
 
[[Category: DEC Hardware]]
 
[[Category: DEC Hardware]]

Revision as of 18:16, 6 June 2019

The H742 Power Supply is a modular power supply system from DEC, used with the BA11-F Mounting Box; among other uses, this mounting box is used in PDP-11/40, PDP-11/45 and PDP-11/70 systems to hold the CPU.

The H742 runs off standard wall AC; it can be jumpered to use either 110V or 220V supply.

The main transformer in the H742 provides 20-30V AC to several DEC standard modular regulators (up to five, in spaces numbered 'A' through 'E') mounted in the H742, which provide other voltages such as +5V to the backplanes in the mounting box.

Generally the power harness supports only limited options as to which regulator can be in which spaces; e.g. the later -11/40 harness mandates that A, B and C hold H744 +5V Regulators, D holds an H745 -15V Regulator, and E may hold either an H745 or H754 +20V, -5V Regulator.

A 5409730 board in the H742 supplies a modest amount of +15V DC power to various backplanes mounted in the BA11-F, along with a line time clock signal, and AC and DC 'power OK' signals.

The harness used DEC power distribution connectors to provide power to the backplanes; it normally used the DEC standard power wire colour coding.

The H742 did not support the Remote Switching Control Bus; the H742 was generally plugged into an 861 Power Controller, which did have the remote control capability.

Later versions of the basic H742 are the H742A and H7420A; the differences are not yet known.

See also