Master/slave power strip, but with 2 masters?

[ouch]

I'm on a bit of an energy saving bender at the moment, and I'm trying to think of a way to synch the power supply in our office at home. The current set up is (at least) 2 PCs with screen(s) a mixer, powered speakers and some other random junk.

Obviously stuff like the monitors and the mixer & speakers don't need to be powered when the PCs are off, however I'd like at least some of them to power up when either of the two PCs start.

I can see loads of power strips with a load sensing master which then switches the slaves of when a threshold load/current is sensed. All very well, but in my case I want 2 masters, and the slaves then switch when either master load increases.

Using an adaptor on the load to run both PCs off 1 socket isn't really an option, most the 'energy saving' power strips I see have a max load of about 500W, which won't really cope with both PCs running IMO, I'd want a max load of at least 1kW, plus I suspect the standby load of 2 PCs might be above or close to the power on threshold as well.

Can anyone recommend a UK product that would do this - i.e. BS1363 plug & sockets and 230V line voltages??

 

[makkem]

Hi
I think you might struggle to do what you suggest with commercially produced units.
If you feel confident with electrics you could make something using two 12V relays in parallel and powering them from the 12V line of each PCs power supply and these in turn switching a high power relay to control the mains power.

 

[jeff-j]

You could look into something like this:

http://lghttp.18464.nexcesscdn.net/808FB7/magento/media/catalog/product/cache/4/image/339x339/9df78eab33525d08d6e5fb8d27136e95/3/2/325727_2.jpg

This should allow the master switch to sense the power being drawn from either computer since it is all straight wires with no circuitry inbetween.

 

[ouch]

Makkem - I was considering something similar, but driven from a spare USB port on each PC (obviously one that doesn't stay live when asleep). My problem is finding the right relays, I'd want double pole to switch live & neutral, and to isolate each port from the other pc I'd need opto-isolators, which then requires an always-up power supply, unless I run an pair of relays in parallel, each driven from it's own seperate USB port,but switching the same load.

Jeff- I've no idea what that is that you've linked to..

 

[jeff-j]

Sorry about that bad link

http://www.monoprice.com/Product?c_id=102&cp_id=10228&cs_id=1022808&p_id=5308&seq=1&format=2

You will just have to find the one to suite your voltage and UK plug needs. This is the US version.

 

[ouch]

Jeff - I can't split the output from the master socket due to the fact they're often limited to about 500W - My PC pulls about 250-300 on its own, so having another running is taking it pretty close to the threshold. Plus I've no idea where they set the lower thresholds on these things, so it could be that 2 PCs in standby pull enough juice for the sensor to think it's one small pc running..

 

[makkem]

Makkem - I was considering something similar, but driven from a spare USB port on each PC (obviously one that doesn't stay live when asleep). My problem is finding the right relays, I'd want double pole to switch live & neutral, and to isolate each port from the other pc I'd need opto-isolators, which then requires an always-up power supply, unless I run an pair of relays in parallel, each driven from it's own seperate USB port,but switching the same load.

Jeff- I've no idea what that is that you've linked to..

I replaced a sensor type socket strip with a relay and used 12V because I could not find a 5V relay capable of switching mains voltage at substantial current.The 12v was taken from a spare Molex.
I looked on Maplin and that still looks to be the case.
You could use a 5V relay for each PC which switch an always on 12V supply which switches the DPDT 12V coil 10A power relay.

 

[ouch]

[
I replaced a sensor type socket strip with a relay and used 12V because I could not find a 5V relay capable of switching mains voltage at substantial current.The 12v was taken from a spare Molex.
I looked on Maplin and that still looks to be the case.
You could use a 5V relay for each PC which switch an always on 12V supply which switches the DPDT 12V coil 10A power relay.

Not too keen on having the always-on 12v supply, as that'll need it's own gubbins to keep it up.

Farnell do 230v relays with a 5v coil:

http://uk.farnell.com/panasonic-electric-works/ale14b05/relay-pcb-tab-spno-5vdc/dp/3727180

However as it's single contact, I'd need 4 for a (2x2) for double pole switching from two computers.

 

[makkem]

If you are prepared to go 12V then RS do a 16A 3PDT.One for each computer.
http://