VAC to VDC Outlet Power Adapters...

[KevinAlaska]

I have a general question about VAC to VDC Power adapters used so often by electronics.

I have a rather now large collection of the power adapters. I need to use one for my linksys router. It uses a 12 VDC, 500 mA power supply with a positive center of the post.

If I use another power adapter that has a 12VDC, 1000mA power supply with the same positive center terminal of the same size, would it work fine?

Is the current rating just a max rating of what the power supply can give before maybe burning out?

Is there any other concerns about power adapters I am not aware of? I know some chargers for laptops are very specific but isn't VDC just VDC as long as the plug is the same and the voltage the same?

Kind Regards

Kevin

 

[Speakerguy]

Yes, should work fine. The current rating is a maximum.

 

[MikeMl]

The question is: does DC = DC = DC???

Some are half-wave rectified with no filter capacitor
More are full-wave rectified with no filter capacitor
Some are full-wave rectified with a whimpy filter capacitor
Some are full-wave rectified with an adequate filter capacitor
Some are full-wave rectified with an adequate filter capacitor and a linear regulator
Some are full-wave rectified with an adequate filter capacitor and a switching regulator
Some are a regulated off-line switcher

And others I have forgotten...

 

[ljcox]

I agree with MikeMI.

It is more complicated than you think.

If it is a regulated supply, then there won't be a problem.

But if it is unregulated, then the voltage with no load will be greater than 12 V, possibly 18 V or more.

If an unregulated supply is rated at 12VDC 1000mA, then it means that the voltage will be about 12 V when the current drawn is 1000 mA.

The voltage will be higher for lower currents.

So I suggest that you measure the voltge with no load.

If it is unregulated, then you need to know whether your linksys router can withstand the higher voltage. I think it can, but I can't be sure without seeing the circuit diagram.

 

[KevinAlaska]

Very cool! I have forgotten lots over the years and that really helps bring a good spect of it back to me. That really helped.

Kind Regards,

Kevin

 

[ljcox]

You're welcome

 

[Hero999]

And others I have forgotten...

The only other one I can think of is an unregulated SMPS.

I found one in a mobile phone charger.

It was just a cheap blocking oscillator and a ferrite transformer, with a rectifier and capacitor on the secondary and no feedback or regulation.