Log light sensor burnout

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entropy111
 
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Joined: Thu Dec 26, 2013 1:52 pm

Log light sensor burnout

Post by entropy111 »

Hi all,

I bought the adafruit log light sensor ( http://www.adafruit.com/products/1384 ) and it worked really well off a 9 volt battery with a voltage divider to 4.5v. I could measure low light in dark rooms and then walk out in to the sunlight and the sensor would perform perfectly.

So I thought it'd be even better to hook it up to a universal power supply like this one: http://www.amazon.com/Tronix-ACA1-Unive ... wer+supply

I set it to three volts and shined a cheapo laser pointer on it....it worked for a bit, but then it stopped working altogether.

I'm not sure if:

1) the laser light overwhelmed it.
2) the universal charger burned it out.

I think the universal charger burned it out because when I touched the chip, it was really warm.


Anyone know if the sensor can handle laser light?

Or is more likely that I suck at electronics and should have put a resistor in with the universal charger...

Any help would be really appreciated.

waltr
 
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Joined: Wed Jun 12, 2013 5:01 pm

Re: Log light sensor burnout

Post by waltr »

Is the polarity switch on the power adapter set correctly?
Did you check the Voltage output with your Voltmeter (DVM)?

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adafruit_support_mike
 
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Re: Log light sensor burnout

Post by adafruit_support_mike »

At a guess, I'd say the laser damaged the sensor, producing a short circuit. The short led to the sensor pulling much more current than it should, making it hot.

Laser light is far more concentrated than regular light, so it takes a lot less overall power to do damage.

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