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Power Switch: A Small but Important Question

Posted: Mon Jan 30, 2023 3:09 pm
by bozocyborg

I am nearing completion on a custom case design for my MiSter. One thing I am looking for advice on is the power switch. I would really like a latching on/off switch mounted to the front of this case. I have a custom shape designed for the exterior pushbutton so I am looking at mounting this switch behind the front panel of the case.

I have a bunch of these small switches already:
https://www.amazon.com/dp/B086L2GPGX/

Would these work for a power switch for MiSTer? If not can anyone recommend a better choice?

Once I have a proper switch, do I just wire that in line with one of the DC power wires to make a safe switch (picture below)?

7amXQvQ.jpg

If not, I'd really appreciate any tips or specific recommendations.

I have read about low quality switches causing power issues so I just want to make sure I am doing the right thing to keep everything working as it should.


Re: Power Switch: A Small but Important Question

Posted: Mon Jan 30, 2023 3:20 pm
by MostroW

These switches are rated for 30v 1A, going with the idea that you're using a 5v adapter, i'd recommend looking for a 5v 3 ~ 4A continuous power rated DC power switch(es)?


Re: Power Switch: A Small but Important Question

Posted: Mon Jan 30, 2023 4:29 pm
by bozocyborg
MostroW wrote: Mon Jan 30, 2023 3:20 pm

These switches are rated for 30v 1A, going with the idea that you're using a 5v adapter, i'd recommend looking for a 5v 34A continuous power rated DC power switch(es)?

Thank you for the quick response! Any recommendation on where to look for such a switch? When I search '5v 4a latching switch' I get no results near what I am looking for. Looking at Mouser, it seems like I mostly pull up rotary switches for some reason.

EDIT:

https://www.digikey.com/en/products/det ... LK/8042726

I found this, rated 3A/30V DC. A little larger than I like but do you think these would work?


Re: Power Switch: A Small but Important Question

Posted: Mon Jan 30, 2023 5:07 pm
by Malor

At low voltages, it's the amperage that matters, so MostroW is pointed right at the problem. The switch you have is rated for 1 amp at 30 volts, so it will also be 1 amp at 5 volts. You want at least a 4A switch; you'd probably want one specced larger, for safety, maybe 6A if the difference isn't too costly.

This is likely one of the problems with many of the inline switches, because I bet a lot of them aren't rated for 4 amps. Buying the switch yourself, assuming that it meets its specifications, should avoid the problem.

I'd probably check Mouser, myself; they're on the expensive side, but their stuff works right.

edit: also, be sure your power supply is at least 4A, too. There's hardly ever a reason to go higher than that, unless your situation is unusual. A 6A switch should cover pretty much any imaginable use case.

second edit: if one will fit, an A/C switch is also a good option, and then you'd never have to worry about amperage. At 120V, the Mister draws like a fifth of one amp. A wildly expanded one with a big supply and a Y cable, driving tons of USB peripherals, might draw a third of an amp.


Re: Power Switch: A Small but Important Question

Posted: Mon Jan 30, 2023 8:05 pm
by MostroW

Have a look at:

4A rated switches
or
6A rated switches

i find Digikey's filtering system a tad slow and finnicky, it's lacking ranges for some parameters.
that said, i've seen a lot of people using so called "anti vandalism" buttons which most of them have illuminated buttons or outer rings in different colors which look pretty decent.

and if you've got an IO board or know how to connect them directly to the DE10 you could also tie in some momentary switches for the reset / osd / user button(s).


Re: Power Switch: A Small but Important Question

Posted: Tue Jan 31, 2023 10:30 am
by metalfacemark

I bought a mister double plug into one that has an on/off switch off ebay and it works a treat.

Alternatively I also bought a power plug with a remote that i can just turn on/off with that rather than the switch for my arcade version which is tucked inside.


Re: Power Switch: A Small but Important Question

Posted: Wed Feb 01, 2023 4:21 pm
by bozocyborg

double post


Re: Power Switch: A Small but Important Question

Posted: Wed Feb 01, 2023 4:22 pm
by bozocyborg
Malor wrote: Mon Jan 30, 2023 5:07 pm

At low voltages, it's the amperage that matters, so MostroW is pointed right at the problem. The switch you have is rated for 1 amp at 30 volts, so it will also be 1 amp at 5 volts. You want at least a 4A switch; you'd probably want one specced larger, for safety, maybe 6A if the difference isn't too costly.

This is likely one of the problems with many of the inline switches, because I bet a lot of them aren't rated for 4 amps. Buying the switch yourself, assuming that it meets its specifications, should avoid the problem.

I'd probably check Mouser, myself; they're on the expensive side, but their stuff works right.

edit: also, be sure your power supply is at least 4A, too. There's hardly ever a reason to go higher than that, unless your situation is unusual. A 6A switch should cover pretty much any imaginable use case.

second edit: if one will fit, an A/C switch is also a good option, and then you'd never have to worry about amperage. At 120V, the Mister draws like a fifth of one amp. A wildly expanded one with a big supply and a Y cable, driving tons of USB peripherals, might draw a third of an amp.

I prefer Mouser myself (that's where I got my DE-10!), but had trouble finding anything that seemed appropriate. I think I have the filters correct now.

For more context, the case design has about 3/4" between were the switch will be mounted and the hole for the front button. The button is completely seperate from the switch, a custom part. There is a wall behind the front face where I planned to mount a through-hole project board to solder up some LEDs and the power switch. If needed I can redesign things to hold a larger switch.

I'd love to put in an AC switch. I am using the Meanwell power brick and could in theory store it inside the case, but it would take up a lot of space I was reserving for a USB hub and MT-32pi.


Re: Power Switch: A Small but Important Question

Posted: Sun Mar 26, 2023 9:29 pm
by TheGMan143

I was planning on doing something similar, using a micro ITX case that has an integrated momentary power switch. I'm going to use a MeanWell 5v/12v power supply to power both the DE10 stack, and a powered USB hub that will be mounted in the backplane of the case (removing any USB load completely from the DE10 USB). Far as the power switch goes, I'll have a 110V integrated switch / AC connector plate on the back of the case to feed AC to the internal power supply. For the momentary switch, I was planning on using a 10A latching relay module to allow ON/OFF functionality using the case's existing momentary switch. I'm going to run it on the 12v side to isolate any switching noise from the 5v line - I'll just be using the N.O. side of the relay to switch the 5v power to the DE10 board and the USB hub... I'll fuse-protect the DE10 and the USB hub separately, as the power supply has more than enough overhead to handle both devices and then some.

Links below to the parts on Amazon.

Rear case AC connector / Switch: https://a.co/d/1tp0Pzp
Power Supply: https://a.co/d/gzoaVLm
Latching relay: https://a.co/d/bi3i3Hz