Electrics question

PEJ

PEJ

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I have a bit of kit that runs off an AC/DC transformer plug and the transformer is broken. The supply it feeds is 3.4V and 0.350 Amps. An OEM replacement transformer plug is over £70.00!

I can get transformer plugs off eBay for under a tenner but the closest match I can find is 3V and 1.0Amp. Does it matter if the voltage is a bit lower and the ampage a bit higher? Will it still work OK or will the PCB the power supply goes to get damaged?
 
Pej
The Current rating of the power supply is its max rating so 1.0 amps should be ok .Need to know a bit more detail on what you are powering to know if a lower voltage would be ok.
 
If you are saying it’s only one volt ,then if the op wanted a 1 volt power supply then added just one volt more that would be double ,I am saying I would not over voltage or under voltage ,if it was not so critical then why would they stipulate 3.7 you could just say 3-5 volt . Just my opinion which is mostly wrong
 
Thanks for the advice but I am a bit confused. Superheat say it's OK to go with 3 x the amps and 4.5V as opposed to 3.4V but others seem to disagree with upping the voltage. On the face of it the Amazon one with 200mA seems good but will lower amps mean it won't work?

Just to be clear the plug goes in the 240V "mains" supply, like in a house.
 
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PEJ said:
Thanks for the advice but I am a bit confused. Superheat say it's OK to go with 3 x the amps and 4.5V as opposed to 3.4V but others seem to disagree with upping the voltage. On the face of it the Amazon one with 200mA seems good but will lower amps mean it won't work?

Just to be clear the plug goes in the 240V "mains" supply, like in a house.
Click to expand...
It needs to be higher amps, so if you can find a 3.4 v with the specified voltage then great.

What are you operating ?

I can't see less than 1 v over making any difference whatsoever. You could try 3v s 0.4v under, but these devices are not accurate to 0.1 of a volt, and the terminal voltage will anyway vary with the current draw.
 
PEJ said:
Thanks for the advice but I am a bit confused. Superheat say it's OK to go with 3 x the amps and 4.5V as opposed to 3.4V but others seem to disagree with upping the voltage. On the face of it the Amazon one with 200mA seems good but will lower amps mean it won't work?

Just to be clear the plug goes in the 240V "mains" supply, like in a house.
Click to expand...
Without knowing what this device is it is hard to say.

It needs to be higher amps capability, so if you can find a 3.4 v with the specified current rating or higher then great.

What are you operating ?

I can't see less than 1 v over making any difference whatsoever. You could try 3v s 0.4v under, but these devices are not accurate to 0.1 of a volt, and the terminal voltage will anyway vary with the current draw.
 
You haven't been very clear about the kit that it is supplying.

But, IMO, it is the voltage that is important to match.
The device (whatever it is) will only draw the amount of current that it wants at the specified voltage.
So (without knowing what the kit is), I would concentrate on finding (or building) a power supply of the same voltage (3.4v) and as long as the new power supply is bigger than .35 amps, you will be ok.
But, what is it that the supply is driving?
 
or go for something like this:
https://www.ebay.co.uk/itm/XL6009-D...596-UK-/152991690783?var=&hash=item239f03f01f

step up / down transformer, will work with either 12 or 24V system DC and with the trim you adjust the output to whatever you wish. Using a few of those for various jobs within the boat (mainly dropping and accurately feeding arduinos)

imho, for such small thing there's really NO reason to go for 220V->3.whatever in DC

cheers

V.
 
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