ShorTie
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Switch or not

Wed Oct 09, 2019 2:05 pm

Heck, I'll give an extra 2 bucks per supply if I could get a switch.
Any thoughts on adding one ??

Andyroo

Re: Switch or not

Wed Oct 09, 2019 2:11 pm

Concerns have been raised on here over the drop in current and/or voltage via a switch.

Just use the one on the mains socket :lol:

ShorTie
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Re: Switch or not

Wed Oct 09, 2019 3:18 pm

You got to be kidding me, right ??
Ever here of design spec's.
Like contact ratings ??

Andyroo

Re: Switch or not

Wed Oct 09, 2019 3:22 pm

The other thing you have to consider is the cost.

Not everyone wants or needs a switch so why should the price go up for everyone? Making two versions pushes hidden supply chain costs back that have to be covered from somewhere.

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Re: Switch or not

Wed Oct 09, 2019 4:08 pm

ShorTie wrote:
Wed Oct 09, 2019 3:18 pm
You got to be kidding me, right ??
Ever here of design spec's.
Like contact ratings ??
Yes of course a PSU can be designed with a quality switch that does the job -- at a cost. It's just that experience of existing switched supplies is that (for whatever reason) the switches used are not adequate for the job, and are a common source of supply problems.
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Re: Switch or not

Wed Oct 09, 2019 6:26 pm

ShorTie wrote:
Wed Oct 09, 2019 3:18 pm
Like contact ratings ??
Switches - mechanical ones - are usually rated for their maximum current-breaking capacity, without any mention of resistance.

So one designed for small currents will probably be designed for low resistance in signal circuits, and probably be silver-plated to reduce any oxidation and the resultant signal loss.
Higher current ones will be designed to withstand any arcing as the switch opens, won't be silver-plated, and will possibly rely on any heating caused by the contact resistance to remove any contamination. Any voltage drop in a high current, high voltage circuit wouldn't be noticed.

But for the Pi's power supply, we need upto 3A being broken, with at most 0.25v drop, so maximum 0.08 ohms.
Can your spec guarantee that, for possibly years, and several thousand make-break cycles?

ShorTie
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Re: Switch or not

Wed Oct 09, 2019 9:13 pm

I worked at Airpax for 10 years, http://www.airpax.net/, all we made is circuit breakers and switches.
From big to small.
So I probably have a little more knowledge then most about contacts and construction and such.

So other then cost and supply, I really don't see any reason why not.
But I offered to pay more, and I'm sure there is more out there like me.

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Re: Switch or not

Wed Oct 09, 2019 9:31 pm

I've been using these for a long time with no problems whatsoever:

Yuconn Micro USB with On/Off Switch

I'm using a MicroUSB to C adapter with one on a Raspberry Pi 4.

They now have one that is USB-C:

Yuconn Type-C with On/Off Switch

ShorTie
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Re: Switch or not

Wed Oct 09, 2019 10:27 pm

Kinda proves my point, ah ??
Be nice, put a switch in, lol.

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Re: Switch or not

Wed Oct 09, 2019 10:35 pm

ShorTie wrote:
Wed Oct 09, 2019 9:13 pm
So other then cost and supply, I really don't see any reason why not.
That would make accidentally powering off much easier. Which is a sure way to wreck the OS or the SD, unless the Pi is designed as an appliance.
I have a few Pis in the wild, those under lock and key curiously have a much better uptime than the others. The worst are those powered via a USB charger; people just disconnect the Pi to charge their phones...
No switch for me, thanks.
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Re: Switch or not

Wed Oct 09, 2019 10:54 pm

I've been using the CanaKit switch (https://www.canakit.com/raspberry-pi-4- ... witch.html) on my 2 Pi4s with no problem. Although it may be a bit pricey for some, it seems to be well-made, and CanaKit is quite easy to work with. YMMV
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Imperf3kt
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Re: Switch or not

Thu Oct 10, 2019 12:06 am

ShorTie wrote:
Wed Oct 09, 2019 10:27 pm
Kinda proves my point, ah ??
Be nice, put a switch in, lol.
You can easily do this yourself if you're so desperate to have one. You just need some cable strippers, and a switch with strain relief.

I must seriously ask why though. What's stopping you from moving the additional couple of feet to reach the switch at the wall where you plugged the power supply in...

I'm not against using a switch, I've even been known to use a switch made of... Bare wire twisted around itself.
It's just that this seems incredibly lazy except under very specific use cases (like your power point is behind a large piece of furniture.)
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RossDv8
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Re: Switch or not

Thu Oct 10, 2019 12:28 am

Because I could not get a Pi power supply for he Pi 4 in Australia, I ordered a Vilross case/fan.powersupply kit from Amazon. It has a switch on the Power supply.
Then because I was plugging the power supply into a small power board, which has a switch for each socket - I found I used the inline switch about twice, because the switch on the power board just feels more natural to use,
And now that PiAustralia has the official power supply for about $30, I might finally get hold of one, switch or no switch.
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pfletch101
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Re: Switch or not

Thu Oct 10, 2019 12:29 am

Imperf3kt wrote:
Thu Oct 10, 2019 12:06 am
I must seriously ask why though. What's stopping you from moving the additional couple of feet to reach the switch at the wall where you plugged the power supply in...
Depending where the OP lives, there may not be "a switch on the wall". Switched outlets are the rule (though not universal) in the UK, and I assume that they must be common in Australia. They are exceedingly rare in the US, so a large proportion of Pi users do not have that option.

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Re: Switch or not

Thu Oct 10, 2019 2:25 am

You are right about Australia.
ALL wall sockets here must be switched and all have Active-Neutral-Earth (3 pin).
Power boards however, are sold with switches and without them, and most of us have a power board or two for our phone chargers anyway. If the power board is switched (per outlet) plugging the Pi adapter into one of those means the switch problem is neatly solved. Switch, or un plug - it's the user's choice.
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Re: Switch or not

Thu Oct 10, 2019 2:31 am

RossDv8 wrote:
Thu Oct 10, 2019 12:28 am
Because I could not get a Pi power supply for he Pi 4 in Australia, I ordered a Vilross case/fan.powersupply kit from Amazon. It has a switch on the Power supply.
Then because I was plugging the power supply into a small power board, which has a switch for each socket - I found I used the inline switch about twice, because the switch on the power board just feels more natural to use,
And now that PiAustralia has the official power supply for about $30, I might finally get hold of one, switch or no switch.
If you're paying $30AUD for the official Pi4 power supply, you're being way overcharged.
https://core-electronics.com.au/raspber ... black.html

I will take this opportunity to mention the Raspberry logo is upside down on the Australian version and it bugs me.
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RossDv8
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Re: Switch or not

Thu Oct 10, 2019 2:42 am

If you're paying $30AUD for the official Pi4 power supply, you're being way overcharged.
Aha, they've come down by $5. So now only AUD$25 (I'm regional, so post is $10)
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Re: Switch or not

Thu Oct 10, 2019 11:58 am

ShorTie wrote:
Wed Oct 09, 2019 9:13 pm
I worked at Airpax for 10 years, http://www.airpax.net/, all we made is circuit breakers and switches.
From big to small.
So I probably have a little more knowledge then most about contacts and construction and such.

So other then cost and supply, I really don't see any reason why not.
But I offered to pay more, and I'm sure there is more out there like me.
I used to be in component engineering, specifically reliability engineering. Getting a low cost, high performance switch installed inline in a very low cost power supply is non trivial. I suspect there is reluctance to add cost.

However the key reason there is not switch, I suspect, is that it would encourage folks to just switch them off rather than properly shutdown down the OS. I also suspect that there would be a positive correlation between the folks most likely to do so and the folks least likely to be able to resolve the subsequent issues.

If you want a switch, either use a power bar, buy a good inline switch (they do exist for both USB C and microUSB), splice in your own switch or buy a fancy HAT or SHIM with a switch integrated with monitoring software that correctly shutdown the Pi. I use the power bar for my desktop Pi since I have the Pi, monitor and speakers plugged in to the same power bar. My settop Pi has a toggle switch mounted on the case, my project Pi has an inline switch. All work fine for me.

RossDv8
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Re: Switch or not

Thu Oct 10, 2019 9:53 pm

When I shut down the Pi 4 last night I realised the reason I use the switch on the power board is so that I don;t have to physically unplug the USB-C power connector from the Pi itself, or unplug the power adapter from the power outlet (in this case, a power board).

Since day one, Shutting down the Pi leaves the red LED 'on'. I don;t remember if that happened with the earlier Pis, but with the Pi 4 it means my case fan is still running, and the power LEDs on the SSD are still 'on'.

So I use the switch on the power board,

Do all Pi 4s leave the red power LED 'on' after shutdown, or is this a quirk of mine?

Ok, a few seconds after I hit 'post', logic kicked in. Of course the red power LED is on, it shows that there is power to the board. I always assumed that shutting down the Pi shut power 'use' on the board somehow, but obviously that is a silly notion.

So in my case (literally with a fan in the case) to switch or not is obvious. I need a switch. So one of the switches on the power board it is - for simplicity. It also happens that the same 4 outlet power board has the TV (monitor) as well as the sound system for the Pi.
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Re: Switch or not

Thu Oct 10, 2019 10:08 pm

RossDv8 wrote:
Thu Oct 10, 2019 9:53 pm
Do all Pi 4s leave the red power LED 'on' after shutdown, or is this a quirk of mine?
The power LED indicates the Pi is connected to power (not the booted or shutdown state).
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RossDv8
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Re: Switch or not

Fri Oct 11, 2019 1:47 am

Yes, I answered my own question in the next sentence - instead of just deleting the question.
However, it is worth noting that shutting the Pi down does not shut power to the GPIO pins that power the fan in the case, nor the power through the USB ports, which means that even after shutdown, my fan is running and the SSD is still showing both the red and blue LEDs.

So a switch is more or less mandatory if one has a fan in the case, or on the board, and if you want to cut power to a drive plugged into a USB 3 port.

Not an issue with the earlier Pis because most of them probably never had a fan. I think though, that many Pi 4 users will choose to have a case with a fan, even if it is running on the 3.3V ? pins as mine is, rather than the 5V pins.

I'm back to running overclocked at 1800 and 600 - just out of curiosity, although having run 'standard' and 'overclocked' for more than a week at a time, I really can't see any day to day difference other than about a 7 deg C temperature increase (when overclocked), and will probably drop back to standard.
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BluPI2
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Re: Switch or not

Fri Oct 11, 2019 3:31 am

RonR wrote:
Wed Oct 09, 2019 9:31 pm
I've been using these for a long time with no problems whatsoever:

Yuconn Micro USB with On/Off Switch

I'm using a MicroUSB to C adapter with one on a Raspberry Pi 4.

They now have one that is USB-C:

Yuconn Type-C with On/Off Switch
Have you tested the output? Do those things really output 3 amps? If so, they Look really nice. Might have to pick one of those up.

I gotta say, I would definitely pay more for an Official supply with a switch. I'd rather not switch off my surge protector along with everything connected to it. Its really not a big deal as has been pointed out though, if you want a switch just go aftermarket. There are other options out there. You just have to look for them.
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