Author Topic: ERC Errors complaining  (Read 3852 times)

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Offline ashley.hughes

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ERC Errors complaining
« on: October 01, 2011, 08:52:18 pm »
Hi,

I have built up this diagram



The ERC Error checker is complaining that
Quote
No Supply for implicit POWER pin IC2P V+

Now I get why as the op-amp needs a V+ and V- but where are these pins? or how do I connect to them when I can't see them? The part is a LM324N which is in the default libraries

Any ideas?
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Offline johnmx

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Re: ERC Errors complaining
« Reply #1 on: October 01, 2011, 10:14:13 pm »
Those pins are invisible and thus global. Place two power symbols in the schematic named V+ and V-. Then connect V+ to +12V power and V- to ground.
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johnmx
 

Offline ashley.hughes

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Re: ERC Errors complaining
« Reply #2 on: October 02, 2011, 09:21:53 am »
Thanks I changed the V12+ to V+ and 0V to V- and it keep it all happy thanks for that.

As for the rest of the circuit does it look alright as far as conventions and stuff go?
My Blog -> http://hughesy.net/wp
My Blog has some tutorials for Arduino mainly based around the mac environment, with xBee and  AppleScript
Starting 2nd year Electrical engineering
 

Online ivan747

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Re: ERC Errors complaining
« Reply #3 on: October 11, 2011, 12:52:53 pm »
You left the on-inverting inputs of 3 op-amps floating. This will cause unnecessary power consumption. Put 2 10K (or any value) resistors in series to make +6V and connect all the unused non-inverting inputs to there. You don't connect them to ground because that saturates the transistors inside the op-amp, increasing the power consumption. Leave the inverting inputs as they are right now to make a voltage follower. You can also find a use for them (buffers can be useful and sometimes, adding a separate op-amp just to amplify a signal that was supposed to be amplified on the previous or following stage can correct oscillation problems. Personally, I like to use them as comparators, along with some LED's to indicate some status regardless of it's relevance  ::)).

Is that a VU meter?
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