Date:   11/20/2006 3:42:51 PM ( 18 y ago)
Hits:   2,447
URL:   https://www.curezone.org/forums/fm.asp?i=776915

Yes, I can translate some of this for you.

"I have a 16 volt here --says only Leader electronics on the prong side and class 2
then a model number long.. 481609R03CT then input: 120/AC 60 Hz 20 W
output:16VDC 900 mA"

In all of this, of prime importance is the output info 16VDC 900mA, but for future reference, the 120/AC 60Hz 20W is pretty standard info indicating the supply itself runs from "wall current" IE> the outlets on the walls in most homes in America, 120 volts AC, 60 cycles per second (60 Hertz), and in this case the supply will use up 20 watts of power.

There is a chain-reaction of sorts at work here. It starts with the 120VAC wall outlets... more specifically it starts with the power company providing 120VAC to your house and wall outlets. This wall current is the input to your power supply. You're going to plug a scanner "power transformer" into one such wall outlet. The above indicates your transfomer is designed to run from 120VAC. So far, so good. If it said something like 220VAC, this would indicate you have a transformer designed to operate somewhere like Europe. If the supply indicated "220-120VAC" this is called a "universal supply" that will work in Europe, U.S. and other places with similar standards. Okay, so the supply gets 120VAC input from your power company. This 120VAC gets applied to the power supply's internal circuitry which then converts "transforms" it into 16 volts DC at a max rating of .9 Amps. This 16 volts then gets applied as an input to the scanner via the funky connector previously mentioned. The scanner takes this 16 volts (ideally 15 volts) and applies it's own circuitry with the result being that some hard copy document you have magically appears on your computer in a special scanned-document file. Your scanner is designed to draw up to 1.2 miliamps in doing whatever "stuff" it does. Your supply is designed to provide a max of .9 Amps.

The bottom line here is what your scanner asks for. In this case, it's asking for 15Volts and 1 point 2 amps. The next bottom line is what the supply can supply. In this case, it can supply 16 volts and point 9 Amps. (900 miliAmps is the same as .9 Amps). When it comes to power supplies, a few things to be aware of are what voltage they output and how much current can they output? 16 volts is close enough in your case, 1 volt off will not likely cause any big problems. However, the .9 Amps may (remember that operative word?) be low enough to cause problems.

Just for sake of argument, lets say you found a supply that provides 16Volts and 2.5 Amps. Some people might say "oh no, way too many amps!". However, the device itself (scanner, for example) determines how much current it will "draw". If the device wants to draw up to 1.2 Amps, a 2.5 Amp supply can definitely supply that, and in most cases, it will, it will provide only 1.2 Amps. A power supply will only provide as much current as it's device allows it to UP TO it's stated rating. It always comes down to the device and how much it needs to draw. The volts - you need to match to a supply as close as possible. The amps - you need to match to a supply that provides AT LEAST as much as what the device requires. If the supply can provide more than the device will draw, this is generlaly okay. If the supply can not provide as much as the device will draw, well, there may be a problem, like, the scanner doesn't work at all, or, it may turn on okay and it may work fairly well all the time, or some of the time, it may work well on some days but not Tuesdays, Saturdays and during full moons, all kinds of flaky operation are possible. Your mission, should you choose to accept it, is to try this supply and see what happens.

 

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