Jump to content

Photo

TI replacement power supply


39 replies to this topic

#26 iKarith OFFLINE  

iKarith

    Moonsweeper

  • 271 posts
  • Location:Portland OR

Posted Mon Jun 13, 2016 8:24 PM

Maybe someone with an electronics background can comment...  Is switching the common an acceptable way to do a power switch for this setup?



#27 acadiel OFFLINE  

acadiel

    Dragonstomper

  • Topic Starter
  • 918 posts
  • www.hexbus.com
  • Location:USA

Posted Mon Jun 13, 2016 8:30 PM

Right now mine is being switched by a smart power strip. Plan on hooking up one of those power cord switches when it comes in from China, though. I'm really thinking of just making a dummy power board to fit in the console.

But back to your question, I don't know what happens if you do that. The original switch is a DPST, I believe, and kills the two AC legs after they come in from the external transformer.

#28 acadiel OFFLINE  

acadiel

    Dragonstomper

  • Topic Starter
  • 918 posts
  • www.hexbus.com
  • Location:USA

Posted Tue Jun 14, 2016 4:00 PM

3d804ba8f790f0dac574fc2f86e13367.jpg

Fwiw, these could be replacements for the stock internal power connector. :-)

Wasn't Tursi looking for these a while back?

There's no "latch" on them, but the pitch and size is pretty identical.

#29 marc.hull OFFLINE  

marc.hull

    Stargunner

  • 1,114 posts
  • Location:Oklahoma CIty.

Posted Tue Jun 14, 2016 6:06 PM

Maybe someone with an electronics background can comment...  Is switching the common an acceptable way to do a power switch for this setup?


Switching the common (or ground) is definately not a good practice. Does not isolate the voltage from the circuit only the return path. The only way to eliminate the voltage from the equipment in that scenario is to unplug it.

In the US at least, switching neutrals is illeagle (NEC wise) in most if not all municipalities.

Edited by marc.hull, Tue Jun 14, 2016 6:09 PM.


#30 acadiel OFFLINE  

acadiel

    Dragonstomper

  • Topic Starter
  • 918 posts
  • www.hexbus.com
  • Location:USA

Posted Tue Jun 14, 2016 6:08 PM

Switching the common (or ground) is definately not a good practice. Does not isolate the voltage from the circuit only the return path. The only way to eliminate the voltage from the equipment in that scenario is to unplug it.


Or a triple pole, single throw switch, if such an animal exists. :-) One can probably cut off everything except ground.

#31 Tursi OFFLINE  

Tursi

    River Patroller

  • 4,716 posts
  • Location:BUR

Posted Wed Jun 15, 2016 11:01 PM

3d804ba8f790f0dac574fc2f86e13367.jpg

Fwiw, these could be replacements for the stock internal power connector. :-)

Wasn't Tursi looking for these a while back?


No, I'm looking for cables. I've found and built cables with the exact right connectors before, but I don't want to build cables. ;)

#32 acadiel OFFLINE  

acadiel

    Dragonstomper

  • Topic Starter
  • 918 posts
  • www.hexbus.com
  • Location:USA

Posted Thu Jun 16, 2016 3:14 AM

No, I'm looking for cables. I've found and built cables with the exact right connectors before, but I don't want to build cables. ;)


Yeah, I have to Google how to crimp these and what kind of wire to use.

#33 globeron OFFLINE  

globeron

    Dragonstomper

  • 584 posts

Posted Sun Jun 19, 2016 7:26 AM

I was wondering if it makes sense to find a replacement power adapter (as these special adapters are not easy to find)

(note: this is the one with the big plug,  even for /4 systems there are different adapters).

 

I managed to obtain a broken one, then replaced fuses and it worked for a while, then the smoke came out, replaced that

component and then broke it again and it seems the whole trafo need to be replaced), see pictures:

https://www.dropbox.com/sh/y3kjbw4wzh7ilna/AAARBl0ltQbV2jRb0RXcA5Tba?dl=0​

 

Was wondering with one of the meanwell or similar, to have a new one, but put it still in the "Shoe" housing if it is small enough.

 

(I think it would be safer as well, before we get fire in the house)


Edited by globeron, Sun Jun 19, 2016 7:27 AM.


#34 iKarith OFFLINE  

iKarith

    Moonsweeper

  • 271 posts
  • Location:Portland OR

Posted Wed Jun 22, 2016 8:29 PM

I'd need to take some measurements and compare to an engineering drawing, but I find this:

 

51FTFykjlqL.jpg

 

That's 4PDT, which is more than you need, but you just wouldn't connect the other leg of the switch, and you can leave the 4th pole unconnected as well.  You do need to worry about whether or not that switch can handle the power, and I haven't checked that yet either, but these  do exist.


Edited by iKarith, Wed Jun 22, 2016 8:32 PM.


#35 iKarith OFFLINE  

iKarith

    Moonsweeper

  • 271 posts
  • Location:Portland OR

Posted Wed Jun 22, 2016 8:35 PM

That won't do it electrically, no.  This would.

 

Again, no easily linked datasheet to know if the stem fits.



#36 arcadeshopper ONLINE  

arcadeshopper

    River Patroller

  • 2,426 posts
  • Location:Portland, Oregon USA

Posted Fri Aug 12, 2016 10:53 AM

https://www.jameco.c...tps:CookieLogon



#37 --- Ω --- OFFLINE  

--- Ω ---

    .....................

  • 10,281 posts
  • TI-99/4A Fanatic
  • Location:In the den playing with my FinalGROM 99!

Posted Sat Sep 3, 2016 10:26 PM

Jon - I'd sure love to see the finished project written up complete with photos and a switch that works in a PDF document.  That way for years to come people could download it, follow it's directions with links to all the parts and keep their TI's running. 

 

I've got an idea to modernize a console with this power supply and even add an F18A with an HDMI converter.



#38 --- Ω --- OFFLINE  

--- Ω ---

    .....................

  • 10,281 posts
  • TI-99/4A Fanatic
  • Location:In the den playing with my FinalGROM 99!

Posted Mon May 15, 2017 9:07 AM

Would still like to see a PDF on this project.  

How many others have performed this MOD?



#39 iKarith OFFLINE  

iKarith

    Moonsweeper

  • 271 posts
  • Location:Portland OR

Posted Mon Jun 5, 2017 2:05 AM

 

I think the right way to hook this up is to put it in an enclosure with ventilation and simply add a fuse and power switch to the input.  You can actually get a fuse holder, switch, and IEC power connector in one combined thingy.  Then it's just a matter of wiring the output somehow to your console.

I'm still not quite sure how best to handle the console's power switch, aside from having three poles to switch 12v, 5v, and -5v on and off.  Probably fine to leave ground connected so you don't actually need a 4PST.  I much prefer the ATX-style standby + power signal, but this PSU doesn't have the means to do that.

Wonder though if we could find an even better switch to replace power, maybe one with off, on, momentary that could also provide a reset?  Hmm.  They you might actually need the 4P.



#40 --- Ω --- OFFLINE  

--- Ω ---

    .....................

  • 10,281 posts
  • TI-99/4A Fanatic
  • Location:In the den playing with my FinalGROM 99!

Posted Mon Jun 5, 2017 9:55 AM

As time goes on, more people are going to need this project to keep their own TI system alive and operating.  Getting out in front of this project now, will save uncounted TI's down the road.   I think many will agree that cannibalizing a working and more expensive console is a last result, others may not want to even bother.   

 

 

 

pdflogo.png






0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users