[GreenKeys] BRPE Restoration

Sun Dec 31 11:55:54 EST 2023

Eric;

I was just finishing a message to you on this subject.  Had to dig a bit to figure out your email address!  Thanks for “piping up”!

I was wondering on what basis you chose 28 Vdc to drive the control relays and the various timings implemented in your .ino file?  My BRPEB11 base includes an array of nine top-hat diodes and nine 25 ohm power (wire-wound?) resistors that suggested to me that probably 100 Vdc, as used for Teletype signaling, was intended.  Does your base also include these components?  Does it use the same 24-pin Centronics-style signal connector?

Also, while I can see a bit of your wiring hook-up in the video (https://youtu.be/-aZl8rMT8Aw?t=129), I’d appreciate it if you could share a schematic along with information about conditioning the input from the “synchro-pulse magnet” as well as driving the relays (possibly this is a pair of ULN devices based on what little I can see in the video).

Please do dig up the updated/final code!

Thus far my primary reference documents have been “1154B_BRPE_Parts_Catalog_Jul1960.pdf” and “215B_BRPE_Technical_Manual_May1971.pdf”, neither of which is particularly satisfying regarding relay driving parameters and schematics :-<.  Any information that you could add to them would be greatly appreciated!

Thank you.  Good Health to You and Yours,

paul

From: Eric Moore <mooreericnyc at gmail.com> 
Sent: Sunday, December 31, 2023 11:45 AM
To: Paul Birkel <pbirkel at gmail.com>
Cc: Greenkeys <greenkeys at mailman.qth.net>
Subject: Re: [GreenKeys] BRPE Restoration

https://github.com/emooreatx/Teletype-BRPE

https://youtu.be/-aZl8rMT8Aw

Here you are, code and video. I got the BRPE going full speed later.

I will try and find the updated code from MIT I am now using. Not sure I ever updated github.

-Eric

On Sun, Dec 31, 2023, 6:03 AM <pbirkel at gmail.com <mailto:pbirkel at gmail.com> > wrote:

I was lucky enough(?) to acquire a BRPE21 on eBay.  Some pics at:  https://www.ebay.com/itm/335180419867

It arrived yesterday and “now comes the fun part” :->.  Overall it’s in pretty good shape, as seen in the pics, however two pins are stuck and some others are sticky.  Not too surprising but I’m enthusiastic about having to disassemble this unit down to the punch-block and then getting it back to operational order.  So I’m very interested in hearing from anyone maintaining a similar unit.  The vital information:

Base unit is BRPEB11 (side plate by power switch).

Punch unit is BRPE21 (8 level with three suppression switches).

Motor unit is LMU6 (plate on motor mount).

Motor plate states: 5PA66HV2A / Type: PA / V: 115 / CY: 60/50 / WD: SERIES

Base unit includes 9x top-hat diodes and 9x 25 ohm power (wire-wound?) resistors.  Signal connector is a 24-pin CINCH 57-40240 female with cable retention clips.  Example: https://www.ebay.com/itm/394787953341  The connector is mounted in a wider cutout (but same end-to-end mounting points) so presumably there were alternative connectors in use.  Includes cable retention clips.  Example: https://www.ebay.com/itm/394787953341  Power connector is a recessed socket sporting a center pin plus a pair of curved blades (one locking); I’ve never had any luck matching that style of socket connector so I guess that I’ll need to replace it, unless someone has the right plug, unused.

This unit appears to be a modestly newer than those documented in 1154B_BRPE_Parts_Catalog_Jul1960.pdf (which appears to only document up to the BRPE11 punch and BRPEB8 base) although 215B_BRPE_Technical_Manual_May1971.pdf does seem to apply.

In 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 32 (Figure 1) the population of the back-plate appears to correspond, so I think that PN #114466 may be the matching power plug (however that PN is subsequently described as “Connector, Receptacle (2 Pt)” rather than as the plug).  Note also in the figure the four rubber grommets (PN #154697) affixed to both sides of the base fore(ish) and aft.  What purpose are these intended to serve?

Also in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 33 (Figure 2) note the two-part metal tape reel (PN #146689 “Disk, W/Hub” & #146690 “Disk, W/Flange”) that is used to dispense tape.  I seek one of these, or guidance/experience in creating a substitute.

Also in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 35 (Figure 4) is illustrated the “motor cover” that I’m missing (PN #143092 or perhaps #142991).  Just askin’ …

Finally in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 44 (Figure 7) I’m missing the chad box (PN #142933; appears to be a simple metal bin but the HappyComputerGuy video on YouTube shows one in transparent plastic, which makes a bit more sense) and then on page 45 (Figure 8) the “Guide, Tape” PN #142983 has somehow been broken in half (looks like a lot of metal fatigue; strange).  At least these are parts that I can manufacture for myself … although an original chad box would be a lot nicer than anything that I’ll be able to produce.

Aside from the “parts call”, above, my initial questions:

1.	295B-6504.pdf states that the LMU6 series (governed) motor is AC/DC.  I infer that if I simply supply 120VAC 60Hz the governing components/circuitry will have no adverse effect, but that’s not made clear anywhere.  The curved-blade power socket seems to suggest that this installation was intended for DC operation, so I’m reticent to simply supply AC “and see what happens”.  (Shaft turns freely and depressing the four spring-ball oiling ports appears to indicate the presence of sufficient light-weight oil, so other than modest cleaning the motor assembly appears to be ready-to-go.)  Figure 5 (page 16) in 295B-6504.pdf is the applicable schematic; there’s no evidence of power supply polarization.  Is this correct for DC operation (either orientation is fine)?  Can I simply use AC without any changes?

2.	215B_BRPE_Technical_Manual_May1971.pdf has very little to say regarding how the BRPE was driven (“deserialization" / "receiver set").  Sections 3.05 through 4.02 (page 21 of the PDF) provide a very generic description of signaling, and then Figure 3 (page 22) documents a conceptual diagram including a “SIGNAL REGISTER” with input “SYNCHRONIZING PULSE SENT TO SIGNAL REGISTER” and output “FEED AND CODE PULSES SENT TO MAGNETS”.  I’ve not found any schematics for the BRPE base, however as it houses 9x diodes and power resisters I’m guessing that the code pulses are “typical” 100Vdc’ish signals.  Is that correct?  Note that the https://www.youtube.com/watch?v=-aZl8rMT8Aw video shows a 28Vdc power supply present for some purpose; as it peaks at ~530 mA during operation I presume that it’s the magnet supply.  https://github.com/emooreatx/Teletype-BRPE/ certainly draws that relationship.

Timing of the code vs. feed pulses isn’t stated anywhere, nor their durations.  Figure 2 (Page 20) is rather stylized and implies that the feed pulse is concurrent with the code pulses, which I guess based on initial study of the mechanics could very well be true. Based on the time-line across the top of Figure 3 it appears as if both code & feed pulses start with the synchronizing pulse at 90 degrees before TDC and end ~80 degrees after TDC, so a nominal duration of somewhat under a half-cycle.  It looks like the mechanism deals with offsetting the actual punch and advance actions.  (Yes the Arduino code in GitHub documents one timing approach; I’d like to determine if it’s the proper one …)

The synchronization pulse is just the raw magnetic pickup, so the implementation of the “SIGNAL REGISTER” needs to both amplify/trigger and then create the correctly timed (and gated in the case of the code) pulses.  It would be quite helpful to see the schematic & technical description of the Teletype equipment that implemented this function!

As my primary use-case is based on a TTL source it looks like I’ll need to not only handle the triggering and timing but also opto-isolation of 10x 100 Vdc signals for the various relays (or maybe that’s “only” 28Vdc).  Has anyone here been down this road, even part way, before me?

3.	There really isn’t any documentation that I can find that addresses punch disassembly, cleaning, and reassembly … although proper lubrication is addressed.  I’m not enthusiastic about tackling the breakdown necessary to properly service the punch block/pins lacking documentation.  I’m hoping that I can extract a subassembly that I can simply immerse in solvent or otherwise apply solvent to selected points while working individual pins to get them moving freely, and then relubricate.  Unfortunately I don’t see any way to accomplish this without a pretty complete disassembly :-<.  Suggestions?  I am assuming that a lightweight “sewing machine” oil will be satisfactory when relubricating.  Is that correct?

I do spy https://www.navy-radio.com/tty/brpe.htm so maybe Nick has answers (and more!) to all of my initial questions.

Thoughts, observations, experience, etc. that have a bearing on my BRPE will be much appreciated.  And …

An early Happy New Year!  One hopes that 2024 will be less “interesting times” than 2023.  But hope is not a method …

paul

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