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What max current will the rear USB actually supply 5V at?

Owen Smith

Well-Known Member
I know it says 0.5A but is there a thermal cutout or anything? I want to run a USB powered ethernet switch and they need 0.7 to 1.5A depending on model. I can't mains power the switch as my dad refuses to have another thing powered all the time costing him money. He'd rather do without streaming on their new TV, regardless of what my mum wants (and there's me trying to keep the peace and find a solution).
 
You are still using and paying for the same amount of electricty regardrless of whether it is plugged into the back of the humax or into a socket!

A new TV that doesn't have most of the streaming apps already buit in!?
 
You expect something to supply up to 3 times its rated current and either not work or cause problems?
I tried powering something off the USB socket on my router without really considering the current draw and it appeared to work, so I left it. A few days later I started having persistent line resync. problems, although everything else on it seemed OK. But because it had been a while since, I didn't associate it with the USB. It took me a couple of days of testing, fault-finding and swearing before the penny eventually dropped. More cursing for being so stupid in the first place.

Has the TV not got wireless? Most have because that's all the great unwashed seem to want to use.
Presumably there's internet/wireless there all the time, although I seem to remember you saying he wanted to turn that off but you'd eventually persuaded him not to.
Just tell him he's not spending his money, he's spending your inheritance (and helping heat the house in a miniscule way) and possibly depriving the government of their 40%.
Failing that, not to be so f*ing stupid.
Could you power it from a USB port on the TV?
Which will almost certainly have the same limit?
 
You are still using and paying for the same amount of electricty regardrless of whether it is plugged into the back of the humax or into a socket!
The point is the ethernet switch would only be powered on when the Humax was turned on. So if watching TV either with Humax or on TV for streaming provided they turn both boxes on everything would work. And while the Humax is in standby, the ethernet switch is off.
A new TV that doesn't have most of the streaming apps already buit in!?
Yes it does, as I said I want the TV connected to ethernet for streaming. But I still want the HDR Fox T2 connected to ethernet so that RS works, I set most of my mum's recordings remotely for her.
 
You expect something to supply up to 3 times its rated current and either not work or cause problems?
The front panel USB can do 500mA as well. There's a decent chance I can take 1A from one of the USB sockets provided I don't have anything in the other socket.
Has the TV not got wireless? Most have because that's all the great unwashed seem to want to use.
I live in Cambridge, my parents in Yorkshire. The less there is at my parents that can go wrong the less likely I am to get phone calls asking me to remotely diagnose and fix things.
Presumably there's internet/wireless there all the time, although I seem to remember you saying he wanted to turn that off but you'd eventually persuaded him not to.
We're past that, my mum has an iPhone now and insists on the broadband and wifi being on all the time for her phone.
Failing that, not to be so f*ing stupid.
My dad can go into a mega sulk if you push him too far. It's not pretty.
Which will almost certainly have the same limit?
TV probably can supply more current actually. USB3 sockets can supply a lot more, and must do as a minimum to be USB3 rated.
 
The front panel USB can do 500mA as well. There's a decent chance I can take 1A from one of the USB sockets provided I don't have anything in the other socket.
Possibly, but the Humax publicised user technical specification detail gives a specified maximum of 800mA shared between the two sockets.

This has been discussed before on hummy.tv
 
Possibly, but the Humax publicised user technical specification detail gives a specified maximum of 800mA shared between the two sockets.

This has been discussed before on hummy.tv
Do you have a link to the discussion? 800mA is getting interesting, some ethernet switches draw 700mA.
 
The front panel USB can do 500mA as well. There's a decent chance I can take 1A from one of the USB sockets provided I don't have anything in the other socket.

No, you won't do that. Each socket has its own regulator so the processor can turn the socket off when you command a USB disconnect, and to act as a current limiter for the socket.. I have a T2 where the front socket won't work as the regulator has failed, but the rear socket still works.

You didn't specify if the TV has wifi itself. If it has why use a router? I have my Hummy using a Vonets wifi bridge which I have set up using a PC to set up a static IP, and then connected to my Hummy. I'm using an external power supply as I want to connect other things to the USB, but it came with a cable to use USB power. I would suggest one of these would be a better bet than a router. If the TV doesn't have wifi then get one for the TV as well.
 
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USB devices always connect initially at 0.5A then negotiate if it is possible to go higher. In this case the TV will tell the switch that 0.5A is all it is getting even if the switch is asking the TV for more juice.

So you can always use one of the newer "fast chargers" to power an older device that does not support fast charging and works off a lower amperage. But a more thirsty USB device may not work or work poorly if fed from an underpowered source. But beware if using it to feed some home-built device that does not follow the USB protocol.

As a matter of interest the charging light on my Bluetooth neckband earbuds stopped working so could not tell if they were charging or when they had fully charged. Added a little dongle between the charger and the USB lead with a display that shows the charging status - when that drops to 0.0V I know the earbuds are fully cooked.
 
For the OP I would suggest offering to give their dad a fiver a month which should be plenty cover the increased electricity usage. In fact it would likely not cost that much over a year or several.

Edit: From the AI summary of an online search

A 7.5W appliance running for a year in the UK, assuming a typical usage of 5 hours per day and the current price cap of 24.50p/kWh, would cost approximately £3.35.

And of course the switch will not be running flat out and drawing the full 1.5A or anywhere near that most of the time when in normal use.
 
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No, you won't do that. Each socket has its own regulator so the processor can turn the socket off when you command a USB disconnect, and to act as a current limiter for the socket.. I have a T2 where the front socket won't work as the regulator has failed, but the rear socket still works.
OK that's evidence the front and rear panel USBs have separate regulators. That's useful to know.
You didn't specify if the TV has wifi itself. If it has why use a router?
The new TV will have wifi, they all do. But wifi is less reliable than a cable, and as I said I want to try to reduce phone calls from my parents asking for help getting something working. The less there is to go wrong the better.
 
But wifi is less reliable than a cable
But by how much, and is it at all significant. Probably not. Adding a switch increases the complexity and likelihood of things going wrong as it could get unplugged or turned off.
I would go with wireless and if it causes problems then you can just say "well you refused to accept my prefered solution so you are on your own".
Seems to me like he's acting like a spoilt 5 year old. I would think it's about time he grew up, as he's probably been like it since he was actually 5.
 
But by how much, and is it at all significant.
Wifi has always been a challenge at their house. It was built in 1960 and breeze blocks at the time had a lot of coal fired power station ash in that had high metal content. The internal walls are terrible for blocking wifi. I made things better a year or two ago by finally getting enough cat 6 structured cabling in to get a separate wifi base station (not the broadband router) installed upstairs and above the main living area, this was necessary for mum's phone. Prior to that the wifi was from the broadband router in dad's study in the far corner of the house downstairs, from where it only covered about a third of the house. Dad still wants to go back to that, because the wifi base station is "one more thing switched on and burning electricity". Mum won't let him because of her phone. I'm trying to plan for him going ahead with that anyway.

It doesn't help that my brother, who is an optician, keeps telling dad to get rid of "all this cabled crap" and just use the wifi from his broadband router like normal people do and it will all be less complicated and work fine. What my brother forgets is his house works fine like that because his broadband is in the middle of his house and his walls don't block wifi, whereas I know from past experience what that works like at my parents. Dad thinks my brother is a "power user" and thinks he knows what he's talking about, so may actually do it.
 
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