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4 channel optoisolator NC

fatman57

May 27, 2013
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I have just purchased a 4 channel optoisolator but am unsure as to the pins - my research says NC doesn't do anything, is this correct? Also, I presume HVCC will be my voltage input line (I plan to use +5V) and HGND will be the ground. Does a separate ground need to be wired to GND on the right? Please see image below:
s-l400.jpg


Much obliged for any help!
 

davenn

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I have just purchased a 4 channel optoisolator but am unsure as to the pins

where's the opto ?
on the other side maybe ?

show us the other side
what opto is it ?
 

AnalogKid

Jun 10, 2015
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If you want the isolation benefits of optical isolation, then keep all left side and right side signals completely separate. Do not combine the grounds.

ak
 

fatman57

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If you want the isolation benefits of optical isolation, then keep all left side and right side signals completely separate. Do not combine the grounds.

ak

One thing, as I will only be using a single power supply, and will be using 5V to power both the Arduino and the load on the other side of optoisolator - so in theory they will be connected by ground anyway?
 

AnalogKid

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Note that in post #3, I said ***IF*** you want ground isolation, isolate the grounds (duh). Of course they can be connected, depending on the rest of the circuit requirements. Which are ... ?

ak
 

fatman57

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Note that in post #3, I said ***IF*** you want ground isolation, isolate the grounds (duh). Of course they can be connected, depending on the rest of the circuit requirements. Which are ... ?

ak

Nice one thanks, haven't thought about this much, just running on the assumption that ground will be fine to share...basic idea is: Arduino feeds opto > opto turns PNP MOSFETS and NPN Transistors on > These power a Peltier array. All parts of the system are powered by a single PSU (PC PSU that delivers 400w of 3V, 5V and 12V)

In my ignorance ground isolation isn't really required, but who am I to say. Why would one want ground isolation? Can there be surges through ground that could damage it for example?
 
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davenn

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Cheers! I doubt its 'real' from a known manufacturer, and if it is the workmanship on the soldering isn't really up to scratch :(
I have no idea what you are talking about ???
 

davenn

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Apologies. You linked to a Toshiba datasheet, I don't totally trust the supply chain this part is coming from

but that isn't related to Toshiba or their datasheet, aye ?
 

fatman57

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but that isn't related to Toshiba or their datasheet, aye ?
Correct, and I really appreciate the datasheet as it has helped. Just lightly commenting that whatever logo might be on it I don't trust it.

Still my original question was: what does NC stand for?
 

davenn

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Still my original question was: what does NC stand for?

usually No Connection or on a relay ... Normally Closed

can you trace that pin ... does it have a pc track between it and somewhere else ?
 

fatman57

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usually No Connection or on a relay ... Normally Closed

can you trace that pin ... does it have a pc track between it and somewhere else ?
Amazing thanks! Currently at work but will do when at home.

On multi-layered circuit boards (and I presume this one only has 2 layers) this technique isn't always possible, correct? If yes would I have to resort to using a multimeter?
 

davenn

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On multi-layered circuit boards (and I presume this one only has 2 layers) this technique isn't always possible, correct? If yes would I have to resort to using a multimeter?

it may or may not be easily traceable.... hardest part will be where tracks disappear under the IC
 
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