Future PSU designs

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dhedberg
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Re: Future PSU designs

Post by dhedberg » Fri Jun 29, 2018 8:39 pm

exxos wrote:
Fri Jun 29, 2018 6:07 pm
So I think I may just leave it be, as its going to ramp up costs a fair bit just to prevent the fuse blowing without the PSU being loaded... I mean everyone should know by now swithcmodes don't like being run without a dummy load ;)
I totally agree on this one. Most people will just replace an existing PSU anyways, and never run any experiments with it, so can't see why they would even try to run it without a load, unless they by mistake forget to hook it up to the motherboard. In that case, the fuse can be replaced. Keep the costs low, put a warning text somewhere on the PCB, and ship the PSU with 2 spare fuses. :-)
Daniel, New Beat - http://newbeat.atari.org. Like demos? Have a look at our new Falcon030 demo MORE.

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exxos
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Re: Future PSU designs

Post by exxos » Fri Jun 29, 2018 9:01 pm

dhedberg wrote:
Fri Jun 29, 2018 8:39 pm
I totally agree on this one. Most people will just replace an existing PSU anyways, and never run any experiments with it, so can't see why they would even try to run it without a load, unless they by mistake forget to hook it up to the motherboard. In that case, the fuse can be replaced. Keep the costs low, put a warning text somewhere on the PCB, and ship the PSU with 2 spare fuses. :-)
Yeah, I'm thinking there's only so much "idiot proofing" I can really do without ramping up costs for almost nothing.

I was just testing the voltage clamp idea.. only had 18V zener to hand, so used 20VDC as the overload voltage.. pulls 320mA, so about 6.4watts... doesn't sound much, but burn your finger on the a TIP31 after 30 seconds.. a higher input overload of just 20.80V pulls 640mA, so about 13.31watts... So if someone left it running like that, it could get hot enough to start smoking without a heatsink.

Only option is to mount a SMT one on the board.. even so, it shouldn't be left running that way for long periods like that. Realistically it would only be able to give 1Volt head room anyway... I thought the peak voltages would limit easier than that, but seems not.

So think will just leave it as is. Its only really a precaution. The mains voltage would have to be higher enough to let the DC float up to 20V before it comes a problem.. here that worked out at 245VAC input to the transformer.

So *IF* the mains voltage was higher than 245VAC AND *IF* the PSU was running with no load, then it likely will blow the fuse.. but it shouldn't be run with both those conditions in the first place.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: Future PSU designs

Post by troed » Fri Jun 29, 2018 9:48 pm

exxos wrote:
Fri Jun 29, 2018 6:07 pm
I mean everyone should know by now swithcmodes don't like being run without a dummy load ;)
Hahahaha .. you're too funny :D

Just include a note saying IF YOU DO THIS THE FUSE WILL BLOW OK????

:)

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Re: Future PSU designs

Post by Forgottenmyname » Fri Jun 29, 2018 11:16 pm

In small print, under the fuse write something like

"Remember to plug it in next time dumbass"

Problem solved, no board mod required :lol:

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Re: Future PSU designs

Post by rpineau » Fri Jun 29, 2018 11:28 pm

:lolbig:
Working ones : MegaSTE (68020) / TT030 / Falcon with AB040 & Eclipse / 1040STF
Need testing : Falcon with CT2

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dhedberg
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Re: Future PSU designs

Post by dhedberg » Sat Jun 30, 2018 12:32 am

Forgottenmyname wrote:
Fri Jun 29, 2018 11:16 pm
In small print, under the fuse write something like
"Remember to plug it in next time dumbass"
Problem solved, no board mod required :lol:
Haha! I love that idea! :lol:
Daniel, New Beat - http://newbeat.atari.org. Like demos? Have a look at our new Falcon030 demo MORE.

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Re: Future PSU designs

Post by exxos » Fri Jul 13, 2018 2:07 pm

Small update.

Final PCBs are now on order for this design. So hopefully in the near future they will be in stock in my store :)
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Axnfell
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Re: Future PSU designs

Post by Axnfell » Sun Jul 22, 2018 9:21 pm

Awesome, really looking forward to it,, great work as always and VERY much appreciated...

James

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Re: Future PSU designs

Post by exxos » Tue Jul 24, 2018 8:02 pm

New super sexy PCBs arrived today :) pictures do not do them justice.
Now to find some time to actually build one up...

psu_red.jpg
psu_red.jpg (77.78 KiB) Viewed 788 times
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Axnfell
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Re: Future PSU designs

Post by Axnfell » Tue Aug 07, 2018 12:13 pm

So does this mean that I have to throw my old Blue one out that I got from you last year? Only joking... but will need to buy a new one soon to rebuild yet another toy... great work as always...

James

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