DIY Thermal LPM for under $50

[ARG]

4.7k will work as a replacement for the 5k resistor. You may want to get a multi-turn pot for that 10k pot.

 

[Kalmito]

THX!

I have LM358N
I have to connect 6 and 7 pins in GND or not, because here is
not connected:

And here is connected:

4.7k will work as a replacement for the 5k resistor. You may want to get a multi-turn pot for that 10k pot.

 

[Zeebit]

You could leave it unconnected. Pins 5 and 6 are the inputs of the second opamp. You could also ground them to ensure nothing comes out the other end.

 

[Kalmito]

Please someone check!
Its right connection ?

 

[Kalmito]

but I dont need second opamp , right !?

You could leave it unconnected. Pins 5 and 6 are the inputs of the second opamp. You could also ground them to ensure nothing comes out the other end.

 

[ARG]

Tie the inverting to the negative supply, and the non inverting to the positive to supply to reduce noise, or tie non-inverting to common an tie inverting to the output.

 

[honeyx]

You could leave it unconnected. Pins 5 and 6 are the inputs of the second opamp. You could also ground them to ensure nothing comes out the other end.

Leaving the secound opAmp unconnected or grounding it will cause noise under both circumstates. There is a proper way to terminate unused OpAmps.

 

[Kalmito]

I dont understand this....

this will be good ? :

Leaving the secound opAmp unconnected or grounding it will cause noise under both circumstates. There is a proper way to terminate unused OpAmps.

 

[honeyx]

Where is the problem? The first OpAmp should be conneced like in the pic you quoted but the secound terminated like on the pic I attached.

 

[Kalmito]

In this picture please write me OpAmp (ic2 lm358)
Used pins... because here is dont writed :

Where is the problem? The first OpAmp should be conneced like in the pic you quoted but the secound terminated like on the pic I attached.

 

[ARG]

Leaving the secound opAmp unconnected or grounding it will cause noise under both circumstates. There is a proper way to terminate unused OpAmps.

That is the best option, but it's not entirely necessary for this.

 

[Kalmito]

Everyone else says, now what I do? Please have someone draw a shematik that is functional... :undecided: I'm clueless...

 

[djQUAN]

Just wire it as a buffer and connect it to the output.

 

[ARG]

Everyone else says, now what I do? Please have someone draw a shematik that is functional... :undecided: I'm clueless...

Connect the unused OPAmp like honeyx says, only a couple extra resistors.

 

[Kalmito]

5,6 pins connected to GND witk 1K ,1K resistor... ( green ) , 7pin not used!
Will be good ?

 

[Kalmito]

this is not better ?