AC adaptor

[broadstairsbob]

Hi
The AC adaptor on my wireless router has failed.
I can use a spare adaptor but want to check it is safe to continue to use as the spec differs slightly.
The broken adaptor reports it input as 230v 50hz 95ma.
My spare also has input of 230v 50hz but is 145ma.
Broken adaptor's output is 12v and 1200ma, whereas spare is 15v and 1.2a.
Also the broken one is labelled as an AC adaptor whereas my spare is labelled as an AC/DC adaptor.
Many thanks in advance

 

[jj4091]

I would not recomend using it as ac/dc probably means ac in & dc out as oposed to an ac output of the original.

 

[Monkeh]

Routers don't take AC.

If the 15V unit is regulated, it'll be fine. If it's not, you'll probably break things.

 

[broadstairsbob]

Thanks for the responses - much appreciated.

A guy at my local Maplins also suggested the router didn't take AC.

The back of the router reports '12V AC 1.2A' above the power input.

In the manual the spec is documented as
AC Inputs: Input: 120V AC, 60 Hz
Power Adapter: Output: 12V AC, 1.2A

I think next I'll call the router manufacturer (D-LINK) to confirm and/or source a replacement for the same model adaptor from E-Bay.

 

[Monkeh]

That's.. unusual. Then again, it's a D-Link.

Dump it and get something decent.

 

[Astra99]

I have come across several modems/routers which specify an AC ELV power supply. This, surely, would imply that the first thing on the router's circuit board is a bridge rectifier! Thus, to use a DC ELV power supply in place of an AC one, should have no adverse effect, it would work correctly. Any comments, anyone?

 

[ban-all-sheds]

A guy at my local Maplins also suggested the router didn't take AC.

The back of the router reports '12V AC 1.2A' above the power input.

In the manual the spec is documented as
AC Inputs: Input: 120V AC, 60 Hz
Power Adapter: Output: 12V AC, 1.2A.

The guy at Maplins was clearly wrong, then....

 

[ban-all-sheds]

I have come across several modems/routers which specify an AC ELV power supply. This, surely, would imply that the first thing on the router's circuit board is a bridge rectifier!

Or a transformer!

But even if it's a rectifier, given the attitude of consumer electronics companies to over-engineering, do you want to bet that the diodes have been specced to cope with the load at 100% duty cycle rather than 50%?

 

[ericmark]

I have noted many routers and modems were 12v AC. However the last one was 12V DC. As already said the diode bridge could be overloaded with a DC supply.

As to voltage I have noted in the past how much extra heat is given off when feeding a 7812 voltage regulator with just one volt extra never mind 3 volt extra.

However 12VAC rectified and feed into a large capacitor will give around 17 VDC so 15VDC may well work OK. So what one must decide is it really worth taking a chance. Especially if left on overnight unattended. Personally I would not take the chance with an item often left on 24/7 with often no one in the house.

To run upstairs and switch router on and off when Blu-ray, Lap top, Iphone, PC, plus Nokia are require it is just not what I would want to do.

 

[Astra99]

<Quote> But even if it's a rectifier, given the attitude of consumer electronics companies to over-engineering, do you want to bet that the diodes have been specced to cope with the load at 100% duty cycle rather than 50%?
<End Quote>

A very good point, Ban. I had assumed that each diode was specced to carry the full DC equivalent current! Whiff of gunsmoke and sore foot for me I think.