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AC Wall adaptor 9VDC 1A - Question

Broonox

Sep 3, 2010
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Sep 3, 2010
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230VAC Wall adaptor Output ~ 9VDC 1A, I was wondering if using this when my circuit only uses a fraction of 1A would do any damage to anything. I was thinking that only the required amount of power would come through the adaptor and that the 1A rating was a max. If not, can i use a resistor at the start of the circuit to lower the current from 1A to how ever many milliamps i need?. Thanks
Code:
9V--------------150Ohm-------------20mA-----------20mA----------------20mA-----------------0V
             |                                                                           |
             -------------------Motor---------------------Potentiometer-----------------------
             |                                                100Ohm                         |
             --------------Motor------------------------Potentiometer-------------------------
 

shrtrnd

Jan 15, 2010
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Jan 15, 2010
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Unless there's something particular about the circuit you're driving, it shouldn't hurt it.
Think about it like your power from the wall socket. I'm on 120VAC, I can run a 3W lightbulb or a 300W lightbulb from the same socket.
The 1A rating IS the max rating, not what you NEED to run your device at.
(I'm talking the current here, ...it's a whole 'nother story, if you're trying to run your circuit at other than the 9VDC the transformer (wall adapter) is designed to operate at.
 

Broonox

Sep 3, 2010
5
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Sep 3, 2010
Messages
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Thanks, just the answer i needed! and yea i understand the voltage aspects. Thanks heaps for the fast help, i just hadn't made a circuit that uses a wall adapter instead of batterys so i just needed to make sure. Rep + to you if i knew how :)
 

Resqueline

Jul 31, 2009
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Jul 31, 2009
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The unregulated adapters give the stated voltage at the stated (also max) current. At no load the voltage will rise to 30-40% more. Your circuit seems to be insensitive to that.
 
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