# level shifting circuit

#### MAINAHNOUD

Joined Jul 24, 2019
60
i produced triangular wave from oscilloscope in protus. Then i enter this signal in level shifting circuit, to make it all in positive part, to can use it aas input for arduino. But when i simulated it, shifting level doesn't occurred and the triangular signal as same as signal which from level shifting circuit ( there isn't any change) so why should i do to reach my goal?

#### crutschow

Joined Mar 14, 2008
25,995
For that circuit you would need a negative voltage going to R12, instead of ground, to provide a positive level shift.
How do you expect it to shift otherwise?

A nit: It's easier to follow a circuit diagram if the lines don't have unnecessary jogs, as yours does.

#### dl324

Joined Mar 30, 2015
12,228
What does this mean?

Are you applying an input on that resistor?

Your schematic is atrocious. It would be much easier to read if you drew it more conventionally.

#### ci139

Joined Jul 11, 2016
1,696
basically your design works but make all 4 resistors equal
... or otherwise the gain would affect the level

#### MAINAHNOUD

Joined Jul 24, 2019
60
For that circuit you would need a negative voltage going to R12, instead of ground, to provide a positive level shift.
How do you expect it to shift otherwise?

A nit: It's easier to follow a circuit diagram if the lines don't have unnecessary jogs, as yours does.
i put -9v on it but also doesn't change

#### MAINAHNOUD

Joined Jul 24, 2019
60
What does this mean?
View attachment 203254
Are you applying an input on that resistor?

Your schematic is atrocious. It would be much easier to read if you drew it more conventionally.
yes i put 9v as shown

#### MAINAHNOUD

Joined Jul 24, 2019
60
basically your design works but make all 4 resistors equal
... or otherwise the gain would affect the level
i made all resistor with 100k, but also doesn't change

#### Audioguru again

Joined Oct 21, 2019
2,377
The schematic has many parts hidden behind the grid. Please turn off the grid.
The schematic has parts so far apart that they are all over my neighborhood. Why?

The output will be more positive if you add a positive voltage to R10.

Your circuit attenuates the signal. Then it does not need R12, and R11 and C8 should be a piece of wire.

#### MAINAHNOUD

Joined Jul 24, 2019
60
The schematic has many parts hidden behind the grid. Please turn off the grid.
The schematic has parts so far apart that they are all over my neighborhood. Why?

The output will be more positive if you add a positive voltage to R10.

Your circuit attenuates the signal. Then it does not need R12, and R11 and C8 should be a piece of wire.
Indeed I put 9v on R10.
Do you mean that I should remove R11 and R12? Also, I can't understand what should I do for capacitor?

#### Audioguru again

Joined Oct 21, 2019
2,377
Yes, remove R11, R12 and C8. Connect pin 4 to pin 1 making the opamp a voltage-follower. R9 and R10 can vary the attenuation and amount of level shift.
I looked up your TS951 opamp. Its maximum allowed total supply is 14V but you are destroying it with 30V! Then your simulation software did not read its datasheet and I don't think you did either.

#### crutschow

Joined Mar 14, 2008
25,995
i put -9v on it but also doesn't change
Then something is wrong with the circuit.

#### ci139

Joined Jul 11, 2016
1,696
you didn't look the TS951 specs — it's Vs is +12V (±6V)
sometimes . . . when the op amp is "unipolar" supply one "they" expect the Vss being the GND (not a rule - but a possibility if it still won't work after Vs adjustment)

Last edited:

#### ElectricSpidey

Joined Dec 2, 2017
1,398
Right click on the component and select "edit".

#### Audioguru again

Joined Oct 21, 2019
2,377
The Falstad Sim does what I said thew circuit will do. But why does the circuit use two un-needed resistors?

#### MAINAHNOUD

Joined Jul 24, 2019
60
Yes, remove R11, R12 and C8. Connect pin 4 to pin 1 making the opamp a voltage-follower. R9 and R10 can vary the attenuation and amount of level shift.
I looked up your TS951 opamp. Its maximum allowed total supply is 14V but you are destroying it with 30V! Then your simulation software did not read its datasheet and I don't think you did either.
i made the simulation as you told, but there isn't any change (no shifting occurred)

Joined Mar 10, 2018
4,057

#### MAINAHNOUD

Joined Jul 24, 2019
60
i need level shifting not digital to analog converter