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Topic: help with optocouplers (Read 1 time) previous topic - next topic

dataplex

hey grumpy

i dont really know... but here is the LM schematic http://farm5.static.flickr.com/4084/4844649061_5724da5cce.jpg

is it drawing too much current?
-------http://ulfurhansson.com/

Grumpy_Mike

Ok last time.
How have you wired up the opto isolator to your circuit.

dataplex

hey grumps

here is what my schematic looks like right now, resulting in the puny 5v output from the opto::


i have a TIP120, and wanted to ask you - would this possibly solve my problem?


thanks for hanging in there...
-------http://ulfurhansson.com/

Grumpy_Mike

Well it is better. However if you have an 8R load then you are going to be shipping a fair bit of current into the amplifier.
You can try that but you are likely to get a bit of voltage drop with that arrangement. Measure the voltage at pin 6 with a meter when you turn it on.
I would also have a large capacitor of > 100uF across the supply of that amplifier.

I would go for a PNP transistor sourcing current properly.

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