is it possible to cut off the amperage without affecting the voltage? i want to get a 9V 300mA...
2007-05-13 03:51:58 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Engineering
That 850 mA refers to the maximum current that the adaptor can deliver and you can use it for less than that also. You don't need another adapter!
This question reminded me of the small hole and big hole story attributed to Einstein. It seems he made two holes of different diameters in the compound wall and when asked the reason is reported to have replied that the bigger hole is for the bigger cat and the smaller hole is for the smaller cat! I am sure that story is made up and for fun, but it illustrates well your own dilemma.
2007-05-13 03:57:58 · answer #1 · answered by Swamy 7 · 1⤊ 0⤋
the things that wants 300ma will take just that - the fact that the adaptor could pwer more will not matter.
It is the voltage that must be right, not the current.
For example, a tiny little 12v bulb could be powered from a battery the size of a pencil OR a car battery - that can deliver HUNDREDS of amps.
Just make sure that the polarity is right - some has centre pin positive, others negative. Sometimes the object cannot handle the reverse.
Mark
2007-05-13 04:00:39 · answer #2 · answered by Mark T 6 · 1⤊ 0⤋
use the 850 ma unit,
it will charge up in about 40% of usual time
2007-05-13 04:07:37 · answer #3 · answered by b r 4 · 0⤊ 1⤋
Like the other guys said, you don't need to do anything with it. Just plug in and use as normal.
2007-05-13 05:42:51 · answer #4 · answered by woutie 2 · 0⤊ 0⤋
Use a resistor in parallel with the voltage source.....for your numbers:
9V/R = (850-300)
R ~ 16.36 ohms (make sure it can handle at least 5W of power)
2007-05-13 04:23:27 · answer #5 · answered by thomas7399 2 · 0⤊ 3⤋
BUY A STEP DOWN AUDIO TRANSFORMER AND THE EQUATION SHOULD BE
Np>Ns
2007-05-13 07:00:24 · answer #6 · answered by kirk b 3 · 0⤊ 3⤋