Trying to use transformer in mic preamp with TINA TI

inkl

Member
2019-10-25 9:47 am
Here's the circuit of an amplifier where the speaker is used as a microphone:


[IMGDEAD]https://inus.azureedge.net/temp/Speaker%20preamp%20draft.png?sv=2018-03-28&si=ro&sr=b&sig=fcxsYWGTTFe0BkcLc7lyhrBly6hyDeKIq7AgjWpYUoo%3D[/IMGDEAD]


And this is my TINA simulation:


[IMGDEAD]https://inus.azureedge.net/temp/speaker%20preamp%20tina.JPG?sv=2018-03-28&si=ro&sr=b&sig=OwdBrkWQtSS4smVmiVmfCI9a6CtQvwtec216%2BRtk1jE%3D[/IMGDEAD]


1) I'm not even sure I understood the circuit right. Especially, regarding split voltage source.
2) When I check the simulation in TinaTI is gives me these errors:


- Pin Prim1 of Ideal Transformer TR1 is floating (This node will be grounded)
- Pin Prim1 of Ideal Transformer TR1 is floating (This node will be grounded): Pin 2 of Loud-speaker SP1 is floating (This node will be grounded)
- Pin Prem2 of Ideal Transformer TR1 is floating
- Pin Prem2 of Ideal Transformer TR1 is floating: Pin 1 of Loud-speaker SP1 is floating
I do not understand these errors, can someone please explain what's wrong with it?


The .TSC file is here in case you want to use it.


Thank you!
 
1. What u mean u dont understand split voltage supply? U have a positive 9V and negative 9V supply...
2. I havent used TINA, but in LTspice u cannot float any comppnents. So the primary, or N1, must be connected to GND even if via a very high resistance. There is leakeage in the real world anyways, so 10meg-1giga ohm should do.
It also seems to have issues with the loudspeaker... I assume specs for that part is defined somewhere...?
But should u use a loudspeaker at input for sim? Shouldnt that be a voltage source?
Then again the gain is set with the source impedance and value of P1, so some resistance must be in series with the source.
Perhaps that helps.
 
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