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<div class="moz-cite-prefix">With an opto isolator you're really
just powering a small LED inside the packaging. Something between
1k and 150 ohm will probably not burn it out too quickly - use the
highest resistance that triggers it solidly. And try it without
the arduino first (but with a resistor).<br>
--D<br>
<br>
On 9/22/13 9:22 PM, Phil Spitler wrote:<br>
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Hey list people, I have an electronics question that I wonder if
somebody could help me with.
<div><br>
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<div><br>
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<div>Basically I'm trying to build a high speed photography rig
based on this.</div>
<div><br>
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<div><a moz-do-not-send="true"
href="http://mattrichardson.com/blog/arduino-flash-trigger-parts-list/">http://mattrichardson.com/blog/arduino-flash-trigger-parts-list/</a></div>
<div><br>
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<div>I have fallen at the first hurdle which is to get the
opto-issolator to work.</div>
<div><br>
</div>
<div>I have a feeling it is due to the value of the resistor I'm
using on the input.</div>
<div><br>
</div>
<div>I have followed his instructions but it seems like the
resistor value of 4.7k might be too high.</div>
<div><br>
</div>
<div>I found the data sheet for the opto-issolator here <a
moz-do-not-send="true"
href="http://pewa.panasonic.com/assets/pcsd/catalog/aqw-dip-2-form-a-catalog.pdf">http://pewa.panasonic.com/assets/pcsd/catalog/aqw-dip-2-form-a-catalog.pdf</a> </div>
<div><br>
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<div>And more info here. <a moz-do-not-send="true"
href="http://www.digchip.com/datasheets/parts/datasheet/724/AQW280EH.php">http://www.digchip.com/datasheets/parts/datasheet/724/AQW280EH.php</a></div>
<div><br>
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<div>I used an online resistor calculator <a
moz-do-not-send="true" href="http://led.linear1.org/1led.wiz">http://led.linear1.org/1led.wiz</a> and
put in the numbers that I found in the data sheet (I think) and
it gave me a resistor value of 33 ohms.</div>
<div><br>
</div>
<div>When I use the 4.7k resistor the opto-isolator doesn't do
anything when the arduino pin goes high but I don;t want to use
a much lower value in case I fuck the chip.</div>
<div><br>
</div>
<div>Any ideas?</div>
<div><br>
</div>
<div>Cheers.</div>
<div><br>
</div>
<div>Phil</div>
<div><br>
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<div><span class="Apple-style-span">
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<div><b>Phil Spitler</b> | Creative
Technologist | <b>Bonfire Labs</b>
| t : 415.394.8200 m : 415.571.3139<br>
<br>
<a moz-do-not-send="true"
href="http://bonfirelabs.com/">Website</a> | <a
moz-do-not-send="true"
href="http://www.facebook.com/bonfirelabs">Facebook</a> | <a
moz-do-not-send="true"
href="http://www.linkedin.com/company/235257?trk=tyah">LinkedIn</a></div>
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