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 with the [[BA11-F Mounting Box]] | + | The '''H742 Power Supply''', and later revision '''H7420''', 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 [[PDP-11/40]], [[PDP-11/45]] and [[PDP-11/70]] systems to hold the [[Central Processing Unit|CPU]]. |
| − | [[PDP-11/40]], [[PDP-11/45]] and [[PDP-11/70]] systems to hold the [[Central Processing Unit|CPU]]. | ||
| − | The H742 runs off standard wall [[Alternating current|AC]]; it can be [[jumper]]ed to use either 110V or 220V supply. | + | The H742/H7420 runs off standard wall [[Alternating current|AC]]; it can be [[jumper]]ed 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 [[backplane]]s in the mounting box. | + | The main [[transformer]] in the H742/H7420 provides 20-30V AC to several [[DEC standard modular regulators]] (up to five, in spaces numbered 'A' through 'E') mounted in the H742/H7420, which provide other voltages such as +5V to the [[backplane]]s 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 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]]. | ||
| − | 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. | + | A 5409730 board in the H742, replaced by an [[DEC Power Line Monitor|5411086 board]] in the H7420, 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]]. | ||
| − | 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. | + | The H742/H7420 did not support the [[Remote Switching Control Bus]]; the H742/H7420 was generally plugged into an [[861 Power Controller]], which did have the remote control capability. |
| − | + | A later version of the basic H742 is the H742A; the difference is not yet known. For the H7420, in addition to the board above, the differences are mechanical; a larger cooling fan, and the sheet metal cavity holding it, the board and the transformer is a single unit, not two bolted together, as in the H742. | |
==See also== | ==See also== | ||
Revision as of 14:55, 7 June 2019
The H742 Power Supply, and later revision H7420, 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/H7420 runs off standard wall AC; it can be jumpered to use either 110V or 220V supply.
The main transformer in the H742/H7420 provides 20-30V AC to several DEC standard modular regulators (up to five, in spaces numbered 'A' through 'E') mounted in the H742/H7420, 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, replaced by an 5411086 board in the H7420, 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/H7420 did not support the Remote Switching Control Bus; the H742/H7420 was generally plugged into an 861 Power Controller, which did have the remote control capability.
A later version of the basic H742 is the H742A; the difference is not yet known. For the H7420, in addition to the board above, the differences are mechanical; a larger cooling fan, and the sheet metal cavity holding it, the board and the transformer is a single unit, not two bolted together, as in the H742.
