Adapter Question

[Sceptre]

hey guys,

just finished moving apartments, i seem to have misplaced the adapter for my toshiba cable modem. The adapter was 12v@1A (and that is whats written on theback of the modem).

only adapter i have kickin around is a 12v@1.3A. The modem will only draw what it needs right? this is the max the adapter can actually put out.

TIA


Sceptre

 

[Agent 009]

Euh.. I don't think so... If I understood your problem, you had a 1-A adapter, and now you have a 1.3-A power supply. So if you connect the adapter to the 1.3A power supply, it's very probable that you burn it, giving it .3A more than needed, unless it has some protection inside, like magnitude comparators, or current clippers...

 

[Sceptre]

my modem requires a 12vdc @ 1A power supply (wall adapter). Can i replace that adapter with one rated at 12vdc @ 1.3A?

 

[crust]

In most cases yes, replacing it with nominally more current than it needs is usually ok. The difference is that there is some thevenin impedance in the wall wart. So measured with no load it might be 14V and with a 1A load it might be 12.2 or something (I am just guessing) since most of these arent regulated. The voltage at 1A will probably be slightly different than the original adapter. However, you need to check the polarity of the adapter, some are tip negative, while others are tip positive.

 

[Sceptre]

In most cases yes, replacing it with nominally more current than it needs is usually ok. The difference is that there is some thevenin impedance in the wall wart. So measured with no load it might be 14V and with a 1A load it might be 12.2 or something (I am just guessing) since most of these arent regulated. The voltage at 1A will probably be slightly different than the original adapter. However, you need to check the polarity of the adapter, some are tip negative, while others are tip positive.

the original adapter is center postitive...the replacement i got there is center negative...can't i just cut the wires and reverse them?

 

[crust]

Yes, you could just cut the wires and swap them. One of them probably has a white stripe so you dont get confused.