An Engineer in Wonderland – Full marks for 20mW stand-by

savasocket.jpgTen out of ten to Leeds-based Energy Saving International for its gadget that cuts the power consumption of mobile phone chargers to 20mW once the phone is charged.

20mW is exactly what a mains-powered device should be consuming on stand-by, and nothing more.

It is the sort of loss that is achievable power chips from the likes of Power Integrations and CamSemi, so there is really no excuse to waste more. 

It is particularly good because, as I remember, the most stringent self-imposed phone charger industry stand-by limit is 100mW – although I cannot remember from whence I obtained this ‘fact’.

The Yorkshire firm also does a smart mains multi-socket that allows several mains loads to be turned off at once – in this case by infra-red using an existing TV or DVD remote control.

For this it gets eight out of ten on the Alice Scale as its own stand-by power is 190mW – very very good, but not 20mW.

I looked at smart multi-sockets last year – the type where switching off one main load causes the socket to switch off all the other loads – and as I remember the best was rubbish – close to 1W – and others were far worse.

By the way, Energy Saving International got a grant of £2,500 from CO2Sense Yorkshire, a business support and market development programme funded by Yorkshire Forward and the European Regional Development Fund


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No email addresses are collected for marketing purposes from responses to this blog. I will keep it that way for as long as possible.

Tags: power consumption

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  1. 'Alice'
    August 10, 2010 14:17

    I agree with you Mr Bellsham, and it looks like it is going to happen.
    Mr Muegge of CamSemi tells us so in a reply to this blog that I have posted separately.
    And I also agree that ‘on’ power consumption is important, particularly if a device is going to be on for a large proportion of the day and on-power is a significant (maybe >1% ?) proportion of the load.

  2. August 05, 2010 15:52

    Like the Energy Saving Trust you have concentrated on the standby power of the product, but that’s not the full story!
    How much extra energy is the product using in ON mode? If it uses a simple relay then circa 1W for the coil and its associated power supply.
    Why is the extra ON mode power never stated! and doesn’t the phone charger automatically reduce its consumption when the phone battery is fully charged.
    This device seems marginal in terms of energy saving……….I could not see the purchase price on the website……Does it really exist?

  3. Charlie Bellsham
    August 05, 2010 11:23

    Making a plug and socket to save save power is a step forward, but manufactures need to be pushed to intergrate this kind of circuit in to their products so we can save the energy and materials required to make the adaptor.

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