Pioneer SX-1980, AWR-154/155 power supply re-design
Thanks for the feedback guys, very much appreciated,
4) To start, insert only, the AC [#26,#27,#28], the transformer wires [ORG(2),#22,#23; BRN,#21(centre-tap); GRN(2),#19,#20; BLU(2),#24,#25], and terminal #10(chassis ground)] into the terminal blocks, TB2,3,4,13,15. Tighten the terminal blocks with wires/terminals/ferrules inserted. If your unit has some ceramic caps attached, it is fine to leave them alone.
Cheers
Rick
I did check my instructions, so it was made mention of, nice to know it does not blow up. I also show in my bench test these wires being hooked up.
4) To start, insert only, the AC [#26,#27,#28], the transformer wires [ORG(2),#22,#23; BRN,#21(centre-tap); GRN(2),#19,#20; BLU(2),#24,#25], and terminal #10(chassis ground)] into the terminal blocks, TB2,3,4,13,15. Tighten the terminal blocks with wires/terminals/ferrules inserted. If your unit has some ceramic caps attached, it is fine to leave them alone.
In Sendust's unit, pin 1& 2 were jumped so I hard wired them on the pcb. It was the multi-tap transformer primary version. If it was going to be a one of then that would have been okay except I should have accommodated the pins 1 &2. Just these last few days I did a revision, to add this in as an option and fix a few things to make them easier to assemble, not have to lead form as many bjts.
Cheers
Rick
kevzep
Its all about the Music
Ah...so there are two versions of the SX1980? I was pretty sure you wouldn't have left techs to figure out how to stop the soft start latching on......
Very nice job of the supply though, next level compared to what was in there originally.
Looking at the manual, additional info section,(recall sending that to you Kev, a while back?) shows that there are 5 versions.
HG,S,S/G,KC,KU
iirc it was S/G I worked on.
There 3 different power switches. 4 different transformers. They made ones just for the US military over-seas iirc S or S/G
The US model(KC,KU?) power switch has 2 contacts, one is added to break the connection to the soft-start relay. I am not sure exactly why they did it that way and not the other models, I suspect someone did not like the few seconds for the soft-start to click off, wanted a faster relay off time, anyone else know of a good reason?
If these extra switch contacts fail, it could smoke the soft-start and thermal fuse, as the relay would never close and short out the big R & T/F. Same as a PS fault. There is little current mA to power the relay coil, so should not be hard on the switch contacts.
There was also another PS AWR-155, I think for only the /HG version. I see it uses a larger soft-start R 6.8 ohms, usually for the higher line V settings I assume.
That's it for my 1980 research.
HG,S,S/G,KC,KU
iirc it was S/G I worked on.
There 3 different power switches. 4 different transformers. They made ones just for the US military over-seas iirc S or S/G
The US model(KC,KU?) power switch has 2 contacts, one is added to break the connection to the soft-start relay. I am not sure exactly why they did it that way and not the other models, I suspect someone did not like the few seconds for the soft-start to click off, wanted a faster relay off time, anyone else know of a good reason?
If these extra switch contacts fail, it could smoke the soft-start and thermal fuse, as the relay would never close and short out the big R & T/F. Same as a PS fault. There is little current mA to power the relay coil, so should not be hard on the switch contacts.
There was also another PS AWR-155, I think for only the /HG version. I see it uses a larger soft-start R 6.8 ohms, usually for the higher line V settings I assume.
That's it for my 1980 research.
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kevzep
Its all about the Music
Thats why it wouldn't be unreasonable to assume its not wired that way....
Well I think Tony's solution was good, Paralleling the switch contacts and moving the supply to the other side of the switch....
Very simple.
Not so sure about that, I do question the contact ratings for that switch section however and if both switch contacts have the same AC ratings.
kevzep
Its all about the Music
Yes, I believe the contacts have the same rating, so it seems like a nice simple workaround for that issue.
I am in the process of using this EXCELLENT upgrade power supply in two SX-1980s. I have come across a few small omissions and/or possible oops-s in the schematic for the new board. I'm going to go fully through this process before I try and install it.
Question: Was/is there and updated schematic, and/or notes on some possible documentation issues? Note, I am NOT COMPLAINING. you've done an exceptional job with a low volume, and difficult, task. I'm just asking if any follow-ups were done on the documentation or other notes along the way. If not, perhaps I'll list my findings as I go through the process of checking, and then installing, the boards.
Question: Was/is there and updated schematic, and/or notes on some possible documentation issues? Note, I am NOT COMPLAINING. you've done an exceptional job with a low volume, and difficult, task. I'm just asking if any follow-ups were done on the documentation or other notes along the way. If not, perhaps I'll list my findings as I go through the process of checking, and then installing, the boards.