VOGONS


First post, by AEV80

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Hi guys, I've put an AT power only Socket 7 motherboard in an ATX case with an ATX PSU.

I'm using an ATX to AT adapter cable which feeds thru to a normal on/off switch.

I'd like to be able to use the momentary power switch on the ATX case instead.

Could someone point me in the right direction to buy an adaptor board / cable for this or some DIY instructions to make my own?

Reply 1 of 11, by detritus olentus

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https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

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https://archive.org/details/@detritus_olentus
Philly Burbs.

Reply 3 of 11, by konc

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detritus olentus wrote:

https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

But where do you connect it?

Reply 4 of 11, by Thermalwrong

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If the board is a super socket 7 board, those often have a concept of soft-power so they might have a header for it, but they'd need to be connected to the ATX connector rather than the AT power connector.

If it's a regular socket 7 AT board, it's probably going to require an arduino to achieve the same soft-power functionality (momentary press = on, 4 second hold = power off).

Otherwise, since it's an ATX case which I assume has one of those little plastic momentary switches for its power button, what could work would be the reverse of what "detritus olentus" suggested.
i.e. A small plastic switch with a latching rather than momentary function - like this: https://www.ebay.co.uk/itm/322017461593

Last edited by Thermalwrong on 2019-01-15, 10:35. Edited 1 time in total.

Reply 5 of 11, by AEV80

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I'm thinking of adapting this circuit https://www.edn.com/design/power-management/4 … tary-pushbutton
or something similar as there are few ways todo it from googling. It would use the ATX case button (momentary button) to toggle a transistor on and off to to drive PSON (green wire on ATX 24pin cable) high or low. It will be hooked up to the to the AT to ATX adapter (the ones with the two terminal cables to hook up to a normal switch).

But if there's already a premade solution I'd use that instead, just haven't found one.

Reply 6 of 11, by AEV80

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Thermalwrong wrote:

Otherwise, since it's an ATX case which I assume has one of those little plastic momentary switches for its power button, what could work would be the reverse of what "detritus olentus" suggested.
i.e. A small plastic switch with a latching rather than momentary function - like this: https://www.ebay.co.uk/itm/322017461593

That would be much simpler 😀
I'll probably go that way.

Reply 7 of 11, by Emu10k1

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detritus olentus wrote:

https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

konc wrote:
detritus olentus wrote:

https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

But where do you connect it?

Black and green cables from the ATX to AT adapter go on to the switch. Those switches usually have a "1" and a "2" mark where the pads are, just put the cables on the pads that are aligned around one of the numbers.

Reply 8 of 11, by konc

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Emu10k1 wrote:
detritus olentus wrote:

https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

konc wrote:
detritus olentus wrote:

https://www.amazon.com/Switch-Power-Style-Pus … n/dp/B000NWFEZQ

I've used one of those before if that's any help? Mounts like AT but functions with ATX power supply.

But where do you connect it?

Black and green cables from the ATX to AT adapter go on to the switch. Those switches usually have a "1" and a "2" mark where the pads are, just put the cables on the pads that are aligned around one of the numbers.

Ah I see. Thank you for the explanation

Reply 9 of 11, by gdjacobs

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A latching switch is definitely the way to go, although a design using a bubblegum logic flip flop and a Zener regulator (or 7805) would be the simplest way using semiconductors.
Re: Cyrix Instead - Desktop Build

All hail the Great Capacitor Brand Finder

Reply 10 of 11, by SirNickity

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I'm actually thinking of building a little 5VSB circuit that I can install in my AT PSUs. I really don't love having mains voltage cables snaking through all the crevices in my old cases. There are so many sharp edges...

But this is one of those things I would go and design, maybe even order components for, then never get around to ordering PCBs and putting it together. Meh. Who has the time? 😁