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PSU info please

Community Veteran
Posts: 17,014
Thanks: 1,211
Fixes: 13
Registered: 06-11-2007

PSU info please

I have a shortwave radio, that is powered by a 13.5v regulated power supply unit. It has an illuminated rocker switch on it, to show it is sending power to the radio  when illuminated. It is permanently plugged into an unswitched wall socket.
When the switch is on, and illuminated, on the psu, BUT the radio is not switched on is the PSU using electricity?
6 REPLIES
Community Veteran
Posts: 6,735
Thanks: 12
Registered: 02-02-2008

Re: PSU info please

Inevitably. How much will depend on its detailed design.
Community Veteran
Posts: 38,307
Thanks: 972
Fixes: 57
Registered: 15-06-2007

Re: PSU info please

Yes but not much I believe
The reason I suggest that is that the transformer/rectifier part will still be working even though there is no final output
You can always get an indication by seeing how warm it gets when switched on when the radio isn't
Community Veteran
Posts: 17,014
Thanks: 1,211
Fixes: 13
Registered: 06-11-2007

Re: PSU info please

Hi Jim
Well, it has been "on" for most of the day, and is "only just" a bit warm... so I don`t think it would be using much....  was just a query, as I forget to switch it off when I have finished using the radio...
it is similar to this one http://www.maplin.co.uk/p/maplin-41w-dc-fixed-voltage-bench-power-supply-xm20w
and the radio only draws about 2 watts when running.....
Thunderclap
Grafter
Posts: 673
Registered: 08-09-2008

Re: PSU info please

On the plate you might find a rating that says "No Load Wattage" or "Quiescent Consumption".
To nail it though, you'll need a power monitoring plug, -
Like this one at Maplin http://www.maplin.co.uk/p/15a-plug-in-energy-saving-monitor-l61aq ; - or check out eBay.
Maybe you can get a cheap/free one through your energy supplier?
Sometimes these monitors show real surprises; our Epson printer when in 'standby/off' was drawing the same energy as a 40W lightbulb. It's now gone to Silicon Hell - express.
Community Veteran
Posts: 6,307
Thanks: 86
Fixes: 3
Registered: 08-01-2008

Re: PSU info please

Quote from: Thunderclap
our Epson printer when in 'standby/off' was drawing the same energy as a 40W lightbulb. It's now gone to Silicon Hell - express.

Just unplug the blighter!!!
It'll take a good while to recoup the cost of a new printer in electricity savings but they don't need to be plugged in all the time anyway.  PULL THE FLIPPING PLUG!  Even accounting for the calories used in walking to the printer and unplugging it and the price of staple foods and the body's relatively poor energy conversion efficiency this seems an obvious solution to me.  Lips are sealed
Call me 'w23'
At any given moment in the universe many things happen. Coincidence is a matter of how close these events are in space, time and relationship.
Opinions expressed in forum posts are those of the poster, others may have different views.
Thunderclap
Grafter
Posts: 673
Registered: 08-09-2008

Re: PSU info please

That Epson was a piece of sCrap anyway. Many people don't realise how much power their scanner/printer thing is consuming. You're right turn it off. Anyway, elecronic devices are made for the American market where every kilowatt hour of electricty comes with a free bucket of regular Pepsi and fries.