12V from OPAMP with arduino?

Thread Starter

Dj Leon

Joined Jan 18, 2020
17
Hey, so I've got a lm358 OPAMP ,a variable power supply and an Arduino with a DAC and I was wandering how to wire the OPAMP to be able to output up to 12v from it when receiving an input from the Arduino. acting essentially as a voltage amplifier. I've looked online and I cannot find what I'm looking for without getting confused. (the output would have to change depending on the input voltage supplied by the Arduino)

Any help would be appreciated. thanks.
 

Dodgydave

Joined Jun 22, 2012
9,079
A Non invering op amp configuration will work, you need to supply the Lm358 with 12V or higher,,

What voltage signal are you inputting?



Q9Dib.png
 

AlbertHall

Joined Jun 4, 2014
9,633
To be sure of getting 12V output from an LM358 you need more than 12V supply - perhaps 16V, it depends on what load you would have on the output.
 

Thread Starter

Dj Leon

Joined Jan 18, 2020
17
A Non invering op amp configuration will work, you need to supply the Lm358 with 12V or higher,,

What voltage signal are you inputting?
what do you mean by voltage signal?
I'm inputting anywhere from 0 to 10v and I need to output up to 12v I can output up to14v from my power supply although I can up that.
 

crutschow

Joined Mar 14, 2008
24,716
Still not totally clear.
Do you want 0-10V at the op amp input to be 0-12V at the op amp output?
If so then you need an Av gain of 1.2 for the circuit Dd posted.
 

Alec_t

Joined Sep 17, 2013
11,141
Be aware that you can't draw much current from the output of that op-amp.
What DAC are you using and what is its supply voltage?
 

dendad

Joined Feb 20, 2016
3,427
And the LM358 will have trouble going down to 0V as well.
A better OPAMP can help, but generating a -Ve supply for the OPAMP will allow the output to go to zero is you need that.
But, can your DAC run on a higher supply or VREF to output the 12V directly?
 

Thread Starter

Dj Leon

Joined Jan 18, 2020
17
And the LM358 will have trouble going down to 0V as well.
A better OPAMP can help, but generating a -Ve supply for the OPAMP will allow the output to go to zero is you need that.
But, can your DAC run on a higher supply or VREF to output the 12V directly?
Nah im using a cheap ebay pwm to analog DAC, takes 12-20v supply input and puts out up to 10v with no way to increase it.
 

dendad

Joined Feb 20, 2016
3,427
If it is one of these...
PWM_ANALOG.png
I'd be tempted to change R13 to a 150K and see if that works.
Or add a 250K across the 100K to the left of the regulator.
At least I think those will be the resistors. Without actually having on to play with, it is a bit hard to work out.
Also, change the reg to a 15V one.

EDIT: This is sort off what it is...
https://www.codrey.com/electronic-circuits/pwm-to-voltage-module-v1/
So far, I have failed to find the actual circuit.
 
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