[Noisebridge-discuss] Electronics Question

[Phil Spitler]

With some help from Mitch tonight I dug a little deeper into the issue.

Basically the OptoIsolator (opto-relay) seems to be working, we measured resistance across the output pins and when we powered it up the resistance went to ~26ohms.

So, I got a 27ohm resistor and used that to short out my flash unit and it fired but still when I connect the flash unit across the output of the optoIsolator it doesn't fire.

Is anybody up for giving me hand at Noisebridge to troubleshoot this? I would love to solve the mystery and get tis part of my project sorted.

Much appreciated.

Phil



Phil Spitler  |  Creative Technologist   |  Bonfire Labs  |  t : 415.394.8200  m : 415.571.3139

Website | Facebook | LinkedIn










On Sep 22, 2013, at 9:46 PM, Davidfine wrote:

> 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).
> --D
> 
> On 9/22/13 9:22 PM, Phil Spitler wrote:
>> Hey list people, I have an electronics question that I wonder if somebody could help me with.
>> 
>> 
>> Basically I'm trying to build a high speed photography rig based on this.
>> 
>> http://mattrichardson.com/blog/arduino-flash-trigger-parts-list/
>> 
>> I have fallen at the first hurdle which is to get the opto-issolator to work.
>> 
>> I have a feeling it is due to the value of the resistor I'm using on the input.
>> 
>> I have followed his instructions but it seems like the resistor value of  4.7k might be too high.
>> 
>> I found the data sheet for the opto-issolator here http://pewa.panasonic.com/assets/pcsd/catalog/aqw-dip-2-form-a-catalog.pdf 
>> 
>> And more info here. http://www.digchip.com/datasheets/parts/datasheet/724/AQW280EH.php
>> 
>> I used an online resistor calculator  http://led.linear1.org/1led.wiz and put in the numbers that I found in the data sheet (I think) and it gave me a resistor value of 33 ohms.
>> 
>> 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.
>> 
>> Any ideas?
>> 
>> Cheers.
>> 
>> Phil
>> 
>> Phil Spitler  |  Creative Technologist   |  Bonfire Labs  |  t : 415.394.8200  m : 415.571.3139
>> 
>> Website | Facebook | LinkedIn
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> Noisebridge-discuss mailing list
>> Noisebridge-discuss at lists.noisebridge.net
>> https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss
> 
> _______________________________________________
> Noisebridge-discuss mailing list
> Noisebridge-discuss at lists.noisebridge.net
> https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.noisebridge.net/pipermail/noisebridge-discuss/attachments/20130923/d35241cf/attachment-0003.html>