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need help with dc adapter

hexacode

Aug 14, 2013
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long story short. im at a thrift store and found a router needing 12v dc and 1 amp.
theres a separate section in store with adapters and i found only 1 12 v dc adapter but its at 200 miliamp. i know for a fact that amp is dictated by the resistor on the circuit, in this case the wifi adapter would be the resistor. so question is will the device, rated at 12 ohms obviously, try to let through 1 amp with the adapter? also, does the 200 miliamp meand just dont go over else it gets fried? or does the adapter have some built in resistor limiting it at 0.2 amps or some other limiting mechanism ?
 

davenn

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Sep 5, 2009
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hi there
welcome to the forums :)

long story short. im at a thrift store and found a router needing 12v dc and 1 amp.
theres a separate section in store with adapters and i found only 1 12 v dc adapter but its at 200 miliamp. i know for a fact that amp is dictated by the resistor on the circuit, in this case the wifi adapter would be the resistor.

well yes ... the LOAD on a circuit diagram may be shown as a resistor BUT don't be fooled
you can also have inductive loads and for that matter capacitive loads ... or a mixture of all 3.
The thing to remember is ... the combination of ALL the components is a device make up the load and unless its something specialised like say an
antenna. then the load can be generally though of as an overall resistive load

so question is will the device, rated at 12 ohms obviously, try to let through 1 amp with the adapter? also, does the 200 miliamp meand just dont go over else it gets fried? or does the adapter have some built in resistor limiting it at 0.2 amps or some other limiting mechanism ?

It will try to draw 1A from the power pack but of course if the pp cannot supply it, then the device wont work properly.
Yes, a pp rated at 200mA means that is the max load before the pp starts to heat up and yes may cook.
No, not usually any resistor in there limiting the current.
The main current limiting comes from the ratings of the transformer in the pp
Secondary will be a voltage regulator ( if present), will also have a current limiting feature

cheers
Dave
 
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hexacode

Aug 14, 2013
2
Joined
Aug 14, 2013
Messages
2
long story short. im at a thrift store and found a router needing 12v dc and 1 amp.
theres a separate section in store with adapters and i found only 1 12 v dc adapter but its at 200 miliamp. i know for a fact that amp is dictated by the resistor on the circuit, in this case the wifi adapter would be the resistor. so question is will the device, rated at 12 ohms obviously, try to let through 1 amp with the adapter? also, does the 200 miliamp meand just dont go over else it gets fried? or does the adapter have some built in resistor limiting it at 0.2 amps or some other limiting mechanism ?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Just a random thought hexacode, but checking your original thread before asking exactly the same question a second time would seem to be... wise?
 
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