reduce your phone bill - please read!

[Ivan]

Actually, reduce the power consumption of your wireless phone handsets or any other item that's on constant standby (eg torch chargers, baby monitors, fax machines, 2nd TV transmitters for Sky box, security cameras, etc etc). Now is a good time to search out your standby transformer supplies and replace with switch-mode supplies.


Several years ago, I bought a set of 4 wireless handsets. A couple of years ago, I decommissioned two of the handsets and rotated the 4 handsets in the two chargers so that the phones were all charged regularly but from two chargers rather than from four.

Each charger uses 4W minimum (you can feel the heat from the plug-in transformer) - so for 4 chargers, a load of 16W, which over a year equates to 140kWh - which would cost me £21/year, at current prices.

I've cut the cost in half by decommissioning two stations, but I'm still using 70kWh/year in standby - so I decided to improve matters.

I purchased a 9v 1000mA switch mode power supply from ebay for £7 incl shipping. Using the Navitron power meter (which is great for measuing very low power consumption), I have established that the new supply uses only 0.4W when trickle-charging the phone (compared to 4W previously) - an reduction in energy consumption of 90%.

So for one charger,  my outlay was £7, the energy saving is 90% ie from 70kWh/year down to 3.5kWh/year - which will save me £9.98/year - thus a payback period of 8½months. (and another 0.2kWh/day off my shrinking daily usage)

It's what you call a no-brainer.

[Greenbeast]

very nice

we got some of those eco phones from siemans or samsung (can't remember) but i don't know if they've tackled the charger issue or whether power savings are purely in the transmit power

i will look into this!

[chester]

Why the difference in efficiencies between the 2 units

Chester

[KLD]

The standard plug-in power supply units use a small transformer. These transformers are not very efficient, especially not the small one. A brief description and a figure can be found here for example.
The transformer is constantly on, even when no load is connected.

Klaus

[Hugo]

I have a Two phone set up with a master and One slave.
I ditched the slave and every couple of days change the phones over for charging.
Going to check out this 9v 1000mA switch mode power supply.

Thanks Ivan.

[petertc]

!"*** or BT phone uses a connector like a small version of an RJ45  , and it's using 4.2 watts
I have one of those multi voltage transformers as well.
Never mind  I'll have to try something else 

[Ivan]

Petertc,

I've never seen a power adaptor that looks like an RJ45, but if you have got one, it shouldn't be difficult to cut the wire and splice in the Switch Mode supply.

My phone charger was using about the same as yours, but I've cut my power consumption by 90% by going to switch-mode supply.

Greenbeast,
I don't imagine even the eco phones will have switch mode supplies, but it's easy to check with a decent power meter (you need a sensitive one, as most powermeters give very inaccurate readings of 4W or below) - the one Navitron sells is the best one I have found.

Another way to check is to feel the plug-in adaptor. If it feels warm, it's a transformer. If it's totally cold, then it's probably a switch mode supply. The switch mode supplies are also a LOT lighter than transformers.

[petertc]

Before i go cutting, switch mode supply is a transformer that allows you to have various output voltages?

[spluger]

NO NO NO


a switch mode is an electronic transformer )think of it that way) so weighs less usually smaller and runs cold

if it feels warm, heavy, big in size, buzzes then its a trany (keep the thoughts clean lads)

also a switch mode will say on the back 110-240volts AC 50-60Hz they're not fussy
where as a trany likes it to be more precise ie 230v AC 50Hz only as output usually depends on input.

got 4 of these pesky things myself

David

PS great post Ivan now i got more jobs todo thanks!!!

[KLD]

!"*** or BT phone uses a connector like a small version of an RJ45  , and it's using 4.2 watts
I have one of those multi voltage transformers as well.
Never mind  I'll have to try something else 

Peter,

The "small version of RJ45" is probably a 6 pole connector, looks similar to the one you connect to the phone line. Our old BT cordless phone (same as a Siemens Gigaset of the same period, ca. y2000) had two of those connectors, too. The plugs on ours are transparent, so you can see how many wires are connected to the plug. The phone line has the two central positions connected, whereas the power line uses the two outer pairs. The PSU provides 7.5 and 9V, so they need two pairs.

Check Wikipedia for RJ11, RJ12.

You can also get the 6-pole connectors plus a crimp tool for not much money ;-)

Klaus

[rhys]

Thanks Ivan great tip. Need new phone
looks like this has switchmode power supplies.
http://gigaset.com/shc/0,1935,xm_en_0_128507_rarnrnrnrn,00.html

[Greenbeast]

well noticed, i have siemans eco-DECT phones

[rhys]

Just need to find a supplier they are not cheap!!

[Ivan]

Good to see them making an effort, but for £7, a switch mode power supply for your existing phone might be a better option - mine uses a fair bit less power than that specified for the eco - phone, and it must be almost 10years old

[wookey]

Note that almost anything you buy new will have an efficient wall wart from April next year (2010) due to   EU regulation   2005/32/EC
which essentially says that off-load consumption must be less than 0.1-0.5W (depending on power output), and efficiency on-load must be bat least  55%-85% (again depending on ouput power).
http://www.powerpax.co.uk/pics/pdf/eup_power_supplies_powerpax.pdf is a good summary

So for new stuff this transition is going to happen automatically. Howerver as Ivan points out, replacing your old crappy wall warts also pays for itself very quickly. Now we just need to work out the best-value/bestefficiency suppliers for the kit.

And of course there is a rapid trend for everything mobile to just use a micro-USB supply so getting a couple of those covers a whole pile of devices.

CPC (http://cpc.farnell.com/) do a comprehensive range from £5 to £25. I rather like the PW02032- PW02041 range which has interchangeable plugs (for UK/EU/AUS/US) and interchangeable outputs (8 DC barrels) and 5/9/12/15/24V (12W) models for £11.20.
Or PW01867 which has the above plus switchable output voltages (3/4.5/6/7.5/9/12) at 2A for £15.78 - that's one supply to do almost anything anywhere.
You can have UK-only single-voltage 1A devices (5/9/12V) for £4.80
The friwo supplies there allow you to buyspecific replaceable DC ends for 38p, which is really nice - normally you have to buy a set of 10 for a fiver to get the one you want.

Sadly most of these don't atually specify efficiency, but you can guarantee it'll be much better than an old wall-wart that gets warm.