Re: Need for testing short something draw 5,10 or 15 amp
I suggest that you get some high power resistors, and use them to limit the maximum current. Much fewer problems than with non-linear loads like LEDs and light bulbs. Also LEDs are kind of inefficient for this purpose. They are intended to be efficient, which is not what you want for your current limiter. You need something that will take more power, unless you just want a hell of a lot of LEDs sitting around...
People (I think some forum members on here have done so too) have made whole arrays of power resistors to load the output of power supplies, for performance testing purposes.
http://www.ebay.com/itm/Lot-of-10-Da...item462b68a01f
All 10 of those in parallel will give you 9.6 amps of current draw, if you have 12V across them.
FYI, they will get hot when you put that kind of power through them! (About 115W)
There are other things to do with the actual circuit you are testing, so this test may not indicate what part is faulty. For example, say a chip that is powered off of 5V has gone short. Also, say that the circuit board has a 12V to 5V regulator on it. That regulator would be overloaded by the short circuit on it's output, and it would get quite hot. But the shorted chip may not get as hot, or maybe not even warm!!! This leads you to a false perception of the regulator being the culprit, when the chip it is powering is the REAL problem.
I suggest that you get some high power resistors, and use them to limit the maximum current. Much fewer problems than with non-linear loads like LEDs and light bulbs. Also LEDs are kind of inefficient for this purpose. They are intended to be efficient, which is not what you want for your current limiter. You need something that will take more power, unless you just want a hell of a lot of LEDs sitting around...
People (I think some forum members on here have done so too) have made whole arrays of power resistors to load the output of power supplies, for performance testing purposes.
http://www.ebay.com/itm/Lot-of-10-Da...item462b68a01f
All 10 of those in parallel will give you 9.6 amps of current draw, if you have 12V across them.
FYI, they will get hot when you put that kind of power through them! (About 115W)
There are other things to do with the actual circuit you are testing, so this test may not indicate what part is faulty. For example, say a chip that is powered off of 5V has gone short. Also, say that the circuit board has a 12V to 5V regulator on it. That regulator would be overloaded by the short circuit on it's output, and it would get quite hot. But the shorted chip may not get as hot, or maybe not even warm!!! This leads you to a false perception of the regulator being the culprit, when the chip it is powering is the REAL problem.
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