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Problem with test load.

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So I built this, using just 4 of the diodes for red:



Everything in my circuit is the same. 4 N4001 diodes. The resistor is 1 ohm, 10 watts. My power source is 3.1 volts (2 AAA's), and I am using the rckstr driver. The polarities of the diodes are correct. When I try to measure the voltage across the resistor though, it reads a constant 6mV no matter how I turn the pot... and each diode reads about .57V...
 

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Well I am building a laser using the LPC-815 diode, I thought 3 volts was enough to power it sufficiently?
 

anselm

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The diode yeah, but the driver "eats" away some voltage too...;)
Try three or even four AAAs, you will see.
 

jayrob

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Well I am building a laser using the LPC-815 diode, I thought 3 volts was enough to power it sufficiently?
Your going to want 2 X Li-Ion's in series.

Or 6 X 1.5 volt batteries in series... (NiMH are best if your going to go that route)
 
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Would a trusty nine volt do the trick? I would like it to be a nice compact size! (and 4 or 6 1.5 volts wouldn't really fit into that category) :p
 

jayrob

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Your only going to have maybe 500mAh's capacity with a 9 volt battery if that...

But I don't think they have much in their ability to provide a high current.

So you will have to test. Probably at lower power, it will work out...
 
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Just tested it with 4 AA's, max I was able to get was about 350mA! All I need really is to get up 450, which should provide more than enough mW for the diode I am using. As for the nine volt... the only one I have on hand happens to be in my DMM... -_- oh well. Hopefully I will be lucky enough for it to draw enough current. If not, I guess I will just go looking for some compact batteries more suitable for lasers!
 

jayrob

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rkcstr drivers are nice drivers. But for tiny builds, you need a FlexDrive. Because you can power it with a single Li-Ion battery...
 
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Good to know. I guess while doing my research I didn't take into account how much the driver itself actually sucked away from the batteries. Its apparent now.... just at 350mA the driver is actually quite warm! Oh well, first builds aren't supposed to be perfect anyways :)
 

Helios

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that driver wont go quite to 500mA unless you modified it. Also stay away from AA AAA 9V C D etc batteries. Your wasting your time with them. Spend $30 and get a quality set of 18650s and charger from larryDFW or buy some cr123a li-ions online.
 

LarryDFW

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Helios;

Thanks for the recommendation.

The Sanyo 18650 should be enough voltage with a good driver.

LarryDFW
 




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