ti99iuc Posted January 5, 2011 Share Posted January 5, 2011 (edited) Hi 99ers ! My 2011 year is started with a new 'Modded' PEB... some one can help me to understand what work it could can do ? i belive that on the rear are the output voltage, but is not only this... into the PEB the PowerAC is completely changed... and isn't the fan ! i post the pictures so you can see and help me to figure out what I can not understand ... ! It seems that are two separated Power AC.... however the back is a label with an inscription in pencil: 7,5/5/12/-+15 What you Think About ? Thank You !!!! , Cix www.ti99iuc.it Edited January 5, 2011 by ti99userclub Quote Link to comment Share on other sites More sharing options...
matthew180 Posted January 5, 2011 Share Posted January 5, 2011 That is probably one of the most dangerous and scary things I have seen in a long time!! The power supply on the top and left side are switching power supplies. The one on the right side appears to be a linear supply and seems to maybe feed the two switchers??? Personally I would not even plug that thing in. Those lug connectors sticking out of the back look very less than safe as well, and internally they are not protected in any way, so they are just sitting there ready to give you a nice solid jolt. Remember, is only takes about 12 "milliamps" to kill you! These power supplies are producing current in the range of 5 to 25 AMPS! Unfortunately the original PEB power supply design was such that each card would do its own power regulation. Thus, each card has a 5V and sometimes 12V and -12V regulators to provide power for that card. Since the input voltage to a regulator has to be higher than than regulated output voltage, the original PEB power supply produced 8V as input for the 5V regulators, and 16V and -16V as input for the 12V and -12V regulators. What that means is, unfortunately, you can't just use a modern switching power supply from a PC to power a PEB, since the modern power supplies output regulated power at 5V, 12V, and -12V (and 3.3V now too). The cards that plug in to the PEB need the higher input voltages for their regulators. This is also complicated by the fact that the PEB power supply does also output regulated 5V and 12V, but only for the disk drive connector, and the current is limited to 1A. My opinion would be to remove all that junk and source a new linear or switching power supply with output voltages in these ranges (lower is better): +5V @ 1A min +12V @ 1A min +7V to +12V @ 7A min for the 5V regulators +14 to +18V @ 2A min for the 12V regulators -14 to -18V @ 1A min for the -12V regulators It is probably really hard to find a power supply with those outputs though, but that mess you have now is just too dangerous. Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 5, 2011 Author Share Posted January 5, 2011 That is probably one of the most dangerous and scary things I have seen in a long time!! Hi Matthew ! Thank You for your Answer... it's the same thing i was hoping to read on this post... It was my opinion too but i was afraid to clean an important modification... so, now i will clean all... But now i will NEED TO FOUND A POWER AC SOLUTION FOR MY NEW PEB ! HAVE SOMEONE a spare power AC for my PEB ? or.. any idea ? i have a project to mount my new HxC SD into a PEB, so this PEB will be good for a more 'normal' modding before I throw all these electronic components into the garbage, someone is interesting in it? ThankYou ! Ciro www.ti99iuc.it Quote Link to comment Share on other sites More sharing options...
nathanallan Posted January 5, 2011 Share Posted January 5, 2011 That looks like someone put those power supplies together to make one from two in one enclosure. Pretty sure it is NOT for the TI computer stuff. It's a shame that the previous owner used a PEB and not a floppy case or some other enclosure. The outputs on the back where the fan was is a dead giveaway to me that this was for something totally else. Maybe a ham radio project. Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 5, 2011 Author Share Posted January 5, 2011 That looks like someone put those power supplies together to make one from two in one enclosure. Pretty sure it is NOT for the TI computer stuff. It's a shame that the previous owner used a PEB and not a floppy case or some other enclosure. The outputs on the back where the fan was is a dead giveaway to me that this was for something totally else. Maybe a ham radio project. Hi Nathan ! The original owner told to me that it wos used for ti99 but with the z80 Board for Cp/m that now i have... but i do not think these modification was needed for work in that modality... the previous owner told me that now him is 80y.o. and do not remember no one other thing... Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 5, 2011 Author Share Posted January 5, 2011 (edited) My opinion would be to remove all that junk and source a new linear or switching power supply with output voltages in these ranges (lower is better): during disassembly of this trap of death ... I saw this card appears to be the only serious good thing in all that junk. What do you think? may be useful for me to feed the PEB? thankyou! Ciro. Edited January 5, 2011 by ti99userclub Quote Link to comment Share on other sites More sharing options...
matthew180 Posted January 5, 2011 Share Posted January 5, 2011 Yeah, I saw that in your original photos. It is nice little linear power supply, but it is only a single output, and only 0.8 Amps. The power supply you get needs to provide all the voltages I specified above: +5VDC @ 1A +12VDC @ 1A +8VDC @ 7A (about 1A per PEB card slot) +16VDC @ 1A -16VDC @ 1A The +8VDC voltage could be anywhere from +7VDC to +12VDC and still work fine. Same with the +16VDC and -16VDC, anywhere between 14VDC / -14VDC and 18VDC / -18VDC should work fine. Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 5, 2011 Author Share Posted January 5, 2011 Yeah, I saw that in your original photos. It is nice little linear power supply, but it is only a single output, and only 0.8 Amps. The power supply you get needs to provide all the voltages I specified above Perfect ! thanks for the advice! I'll try to do something with a my best friend who knows better of me the electronics, we hope ... otherwise I have to start looking for a power supply of AC PEB. Quote Link to comment Share on other sites More sharing options...
marc.hull Posted January 6, 2011 Share Posted January 6, 2011 Hi 99ers ! My 2011 year is started with a new 'Modded' PEB... some one can help me to understand what work it could can do ? i belive that on the rear are the output voltage, but is not only this... into the PEB the PowerAC is completely changed... and isn't the fan ! i post the pictures so you can see and help me to figure out what I can not understand ... ! It seems that are two separated Power AC.... however the back is a label with an inscription in pencil: 7,5/5/12/-+15 What you Think About ? Thank You !!!! , Cix www.ti99iuc.it Before you do anything Ciro here is a bit of valid information.... It appears that the previous owner of the PEB put a PC power supply or two inside the box. This was a fairly common MOD done to reduce the heat on the cards. You would be smart to check any cards that came out of that beast for regulators which might have been removed or jumpered to make the system work with pre-regulated voltages. If you put them into a normal PEB and the regs have been tampered with you will smoke the circuits. .... I would bet that the sockets on the back are for feeding the console (another mod I have seen described.) Gets the power converter and regulators out of the console reducing heat there as well. At any rate check the cards and make sure they have 7805's and 7812's on them and they are not jumpered. The 7905's for -5v were not removed normally because PC power supplies did not normally supply these voltages. What are the voltages at the sockets in the back ? I would guess 5,-5, 12 and ground. Quote Link to comment Share on other sites More sharing options...
+retroclouds Posted January 6, 2011 Share Posted January 6, 2011 Hi, if you have any chance, please please show us some pictures of the Z80 CPM card Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 6, 2011 Author Share Posted January 6, 2011 Hi, if you have any chance, please please show us some pictures of the Z80 CPM card Yes ! I will open a new topic for z80 ... look at ! Quote Link to comment Share on other sites More sharing options...
ti99iuc Posted January 6, 2011 Author Share Posted January 6, 2011 however the back is a label with an inscription in pencil: 7,5/5/12/-+15 What you Think About ? Thank You !!!! , Cix www.ti99iuc.it Before you do anything Ciro here is a bit of valid information.... It appears that the previous owner of the PEB put a PC power supply or two inside the box. This was a fairly common MOD done to reduce the heat on the cards. You would be smart to check any cards that came out of that beast for regulators which might have been removed or jumpered to make the system work with pre-regulated voltages. If you put them into a normal PEB and the regs have been tampered with you will smoke the circuits. .... I would bet that the sockets on the back are for feeding the console (another mod I have seen described.) Gets the power converter and regulators out of the console reducing heat there as well. At any rate check the cards and make sure they have 7805's and 7812's on them and they are not jumpered. The 7905's for -5v were not removed normally because PC power supplies did not normally supply these voltages. What are the voltages at the sockets in the back ? I would guess 5,-5, 12 and ground. Thank You Marc for your information, i have compared the original Disk Controller Card and the Disk controller Card of this PEB for use with z80 Card... This controlle semms to change only for a cable added and nothing more... can you check on the picture if i'm correct ? You can check the z80 card too in the other topic... If you also think about these are the same card i think i can try these cards in a normal PEB, right ? Quote Link to comment Share on other sites More sharing options...
marc.hull Posted January 7, 2011 Share Posted January 7, 2011 however the back is a label with an inscription in pencil: 7,5/5/12/-+15 What you Think About ? Thank You !!!! , Cix www.ti99iuc.it Before you do anything Ciro here is a bit of valid information.... It appears that the previous owner of the PEB put a PC power supply or two inside the box. This was a fairly common MOD done to reduce the heat on the cards. You would be smart to check any cards that came out of that beast for regulators which might have been removed or jumpered to make the system work with pre-regulated voltages. If you put them into a normal PEB and the regs have been tampered with you will smoke the circuits. .... I would bet that the sockets on the back are for feeding the console (another mod I have seen described.) Gets the power converter and regulators out of the console reducing heat there as well. At any rate check the cards and make sure they have 7805's and 7812's on them and they are not jumpered. The 7905's for -5v were not removed normally because PC power supplies did not normally supply these voltages. What are the voltages at the sockets in the back ? I would guess 5,-5, 12 and ground. Thank You Marc for your information, i have compared the original Disk Controller Card and the Disk controller Card of this PEB for use with z80 Card... This controlle semms to change only for a cable added and nothing more... can you check on the picture if i'm correct ? You can check the z80 card too in the other topic... If you also think about these are the same card i think i can try these cards in a normal PEB, right ? It appears that the regulators are there and not jumpered. That's a bit of an odd duck hmmmm. Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.