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46  Using Arduino / General Electronics / Re: 4 digit LED serial display on: February 05, 2013, 08:28:00 pm
What chip is on them a max serial driver i bet DIN is data, load is latch and CLK is Clock. But you'll need to see what chip there using may even be a shift register.
47  Using Arduino / General Electronics / Re: How to load a battery / wall-wart for a voltage test? on: February 02, 2013, 09:13:27 pm
There to kinds of test one to see how long the battery last and two to see if the battery is good.

To see if a battery is good doesn't need a big load to see how long a battery last and is still good the user load would be a better choice.

Testing a  Nicad with a 6 ohm resistor 1/2 watt would be like short not last not very long because the Nicad can dump out amps when shorted needs a 3 watt resistor.
48  Using Arduino / General Electronics / Re: Any experience with LB1641?? on: January 25, 2013, 08:17:49 pm
The fact that the v.reg output drops from 12V to 2V means you do have a serious load on

He is floating the inputs and the zener diode set's the motor voltage.

So if your feeding 12 your burning off half of it some where

I would set up the test circuit http://www.datasheetcatalog.org/datasheet/sanyo/ds_pdf_e/LB1641.pdf
49  Using Arduino / Project Guidance / Re: Send data over USB from iPad to Arduino on: January 24, 2013, 07:42:40 pm
Have you seen this https://itunes.apple.com/us/app/get-console/id412067943?mt=8&ls=1

50  Using Arduino / Project Guidance / Re: Send data over USB from iPad to Arduino on: January 23, 2013, 09:38:06 pm
The iPad Camera Connection kit let's use USB to serial adapters.
51  Community / Bar Sport / Re: So what (grin) resistor should i use for this LED then? :D on: January 20, 2013, 11:49:50 pm
Na the op is using the regulator as a current source and if you read the data sheet on most they lower the voltage to hold there output of current. I posted this before but some people don't read data sheet's  and think that A plus B is C Na A can be A LOL.

      
52  Using Arduino / General Electronics / Re: Usb pcb mount fix on midi drum machine on: January 20, 2013, 03:10:42 pm
Most USB use a ferrite bead on the supply so I would say that's what your looking at It's not going to hurt to use one there.
53  Community / Bar Sport / Re: So what (grin) resistor should i use for this LED then? :D on: January 20, 2013, 10:19:01 am
The Op is basing  this on the total leds looking like 10 ohm load 30 volt 3 amp 10 ohm.

You set it as the leds came on  And it worked it will for now but it may not on the next set.

I played with current driving leds and the voltage idea your using.

I did it like this I hooked 10 red leds in series I supplied 1.5 to 25 volts as I turn the pot led 1 came on
the supply used  lm317   turn it up led 9 came on went for led 10 and on it came.

I sat there and said cool till they popped like popcorn but my supply could put out 3 amps your is limiting the current.  
54  Using Arduino / General Electronics / Re: Protecting Analog Inputs: How often and how bad will it fail? on: January 19, 2013, 12:14:16 am
Quote
Basically, I am using the source-drain resistance of the MOSFET as a current-sense resistor. A crude measurement of the current is all that is necessary.

That's not a real good idea you could read the copper trace resistance would work better and save you a headache

That's the way cheap DVM read it better one's use a wire thats made to have constant reading with temperature.
55  Using Arduino / General Electronics / Re: Protecting Analog Inputs: How often and how bad will it fail? on: January 18, 2013, 09:58:06 pm
I would limit current to under the clamping diodes spec. At the 48 volts
56  Using Arduino / General Electronics / Re: DIY PCB transfer media on: January 14, 2013, 11:13:06 pm
There two ways to use the  vinyl . First one you buy a $400.00 dollar cutter. http://www.instructables.com/id/Fast-and-Easy-PCB-Prototyping-with-Vinyl/

And the one tho OP is taking about the vinyl paper that keeps it from sicking you remove it print on it place the vinyl back on and iron it peel the vinyl place on copper and iron it on then just peel it off and etch. I been looking for the second way can't find the link. http://en.electroni-city.com/
57  Using Arduino / General Electronics / Re: DIY PCB transfer media on: January 14, 2013, 03:48:40 pm
Is this in parts or what I've seen then cut the vinyl and use that I also seen something like the OP is taking about You pull the   vinyl  copy to the backing and they ironed  it back to  the vinyl  then put the vinyl on the copper and ironed that on.

But I have not tried that But I do have the vinyl and I'm going to try this this weekend I wish the OP will post a link.
58  Using Arduino / General Electronics / Re: MOSFET as switch and power monitor on: January 14, 2013, 07:52:15 am
 fungus I was just adding to what you where saying.  In all reality  A  relay be it Solid State or  mechanical. Would give you better heating.
59  Using Arduino / General Electronics / Re: MOSFET as switch and power monitor on: January 14, 2013, 07:35:01 am
@ what fungus said your power loss is more with the P channel then the N channel.
And like fungus  said you can't use just a P channel MOSFET you have to add a driver.
60  Using Arduino / General Electronics / Re: MOSFET as switch and power monitor on: January 14, 2013, 07:09:07 am
Power flows from  negative to positive
Quote
negative charged electrons move toward the positive
So you are cutting off the Power using a N channel

And a a 1 inch piece of 18 gauge wire would  read 10 Millivolts @12 volts 10 amp and and put out 100 Milliwatts of heat I'm sure it's not going to get hot you'll have to scale it with a opamp.

I have a DVM it's not a cheapo and it reads across a 3 inch piece of wire it's 14 gauge   
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