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Use 3 Prong AC/DC converter as power supply

Wotan

Oct 8, 2011
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I am thinking of buying a 3 prong AC/DC converter to use as a power supply for my breadboard, that way I won't have to buy a charger and keep on charging batteries. Is this a good idea and if it is how would I go about making it into a power supply since there are 3 prongs- live, neutral and earth? Thanks in advance for your answers.
 

davelectronic

Dec 13, 2010
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Adapter psu

Hi Wotan.
An AC to DC converter is a power supply, the incoming mains is stepped down then rectified to bumpy DC high ripple component to the wave form, then its filtered with capacitors, and put through a regulator for clean DC output, unless your describing something different ? a normal psu would do, you can build a regulator circuit or by an off the shelf variable unit, cost about £ 25.00 to £ 50.00 pounds in the uk here, 0 to 3 amps, 0 to 30 volts, some voltage is less or a bit more, depends on the circuits you plan to power up.

If this converter thing is different post a picture and its specification.
You might be able to use it, but i am at a loss as to what your converter spec / function is.
Dave. :)
 

Wotan

Oct 8, 2011
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Here is a pic of what i mean ( sorry it's actually called an AC/DC adaptor )

515_0.jpg


I would like to use it instead of batteries but i have to find a way to connect it to the breadboard somehow.
 

davelectronic

Dec 13, 2010
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Ok now i am a bit wiser, yes mains to low voltage AC / DC adapter, there ok for fixed voltages, some only put out one voltage, others have a selector switch, say from 3, 4.5, 6, 9, 12 volts.

As a rule the current drops off as the voltage increases, so say the units 1200 milliamp, some units will give this power level at max voltage, other units wont, for instance another unit might give you 1000 milliamps up to 9 volts, but at 12 volts say 800 milliamps, it pays to read the ratings for max power for given voltages across the whole range.

Yes these units if regulated can power your projects, build a small DC connection box with a DC socket in it in one side and drill some holes and add posts or sockets for 4mm plugs and crocodile clips, add a fuse and switch if you want, a latching switch and a momentary switch for short power bursts is useful.

It very much depends on projects you build, they will work fine for a lot of projects, try and get a good quality one with the voltages above, this gives more options powering circuits, you can always upgrade later, a picture of a box i am on about, this one is fixed for radio use, but you can select what voltage you want for a given project.
Dave. :)

Photo0001.jpg


Photo0002.jpg


Add as many switches as sockets or binding posts, sorry poor pictures, only had a phone camera to hand, but a box like this can allow multiple voltages either by multiple pole switches, or posts / sockets.
 
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davenn

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Sep 5, 2009
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Here is a pic of what i mean ( sorry it's actually called an AC/DC adaptor )

I would like to use it instead of batteries but i have to find a way to connect it to the breadboard somehow.

hi Wotan,

yup no problems, connecting to the breadboard is easy you have 2 straitforward choices :)

1) ... you can snip off the socket that is on the end of the cable, strip a cm of plastic insulation off each end, twist up the wires tight and solder them then snip clean. They will then push easily into the breadboard

2) ... you can choose one of the supplied end plugs , buy a suitable socket for it and solder 2 lengths of wire off the socket ( 1 red 1 black) use a wire that has a solid conductor rather than a multistranded one.

In both situations ensure you identify the correct polarity ( + and - ) of the wires going into the breadboard

The first choice leaves the plugpack (AC-DC adaptor) for use primarily with your breadboard.... You may find that best for your situation.
The second choice means the plugpack still has versatility to be used in the way it was originally intended if you happen to need it occassionally for another purpose.

Your best choice of plugpack would be one that is switched and regulated voltages.
It will ALWAYS state on the plugpack if it is regulated.
For most breadboard experiments you are probably never going to need more than ~ 500mA (0.5A), so aim for one that is rated somwhere between 500mA and 1A

cheers
Dave
 

Wotan

Oct 8, 2011
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Thanks for your replies guys, Davenn- We have 3 prong plugs here so can I do what you said with a 3 prong AC/DC regulated adaptor? ( live, neutral and earth )
 

davenn

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Thanks for your replies guys, Davenn- We have 3 prong plugs here so can I do what you said with a 3 prong AC/DC regulated adaptor? ( live, neutral and earth )

yes I was answering the pic you supplied.
Do the changes I suggested to the low Voltage DC side. There's nothing easy you can do to the AC side. Unless you are well experienced working with mains power. Just plug it into the wall as normal

Dave
 
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