# 0-10VDC to 10-0VDC rescaler circuit

#### circuit89

Joined Sep 17, 2023
2
Hi, I need some help for rescaling 0-10VDC to 10-0VDC modulating signal. for example: input 0VDC =Output 10VDC, 1VDC=9 VDC, 2VDC=8VDC...... 9VDC=1 VDC, 10VDC=0 VDC.

Could anyone help me to build a circuit for this? I can provide 24VAC or DC from external source.

#### ericgibbs

Joined Jan 29, 2010
18,219
hi c89,
Which type of OPA's do you have available?
E

#### Ian0

Joined Aug 7, 2020
8,941
With 24V DC available, you can do it with an LM324/LM358 (about the only thing an LM324/LM358 is good for).
Bias the non-inverting input to 5V with a voltage reference (do you have 5V elsewhere in the circuit you could use as the reference?)
Resistor between output and inverting input (any value between 4.7k and 100k)
Same value resistor between 0-10V signal and inverting input.

#### circuit89

Joined Sep 17, 2023
2
As I am very new to this, could you please provide me a circuit diagram for the same?
With 24V DC available, you can do it with an LM324/LM358 (about the only thing an LM324/LM358 is good for).
Bias the non-inverting input to 5V with a voltage reference (do you have 5V elsewhere in the circuit you could use as the reference?)
Resistor between output and inverting input (any value between 4.7k and 100k)
Same value resistor between 0-10V signal and inverting input.

#### Ian0

Joined Aug 7, 2020
8,941
As I am very new to this, could you please provide me a circuit diagram for the same?

#### crutschow

Joined Mar 14, 2008
33,339
Below is the LTspice sim of Ian0's circuit with a resistor network to generate the 5V bias to the plus input:
Note that since the the LM324 is a bipolar device with a PNP pulling the output low (top circuit), it doesn't go much below 1V minimum (yellow trace) due to the load from the feedback resistor.

To go to 0V output, you need an op amp (such as CMOS types, bottom circuit) that can pull the output to ground (red trace).

#### AnalogKid

Joined Aug 1, 2013
10,778
To go to 0V output, you need an op amp (such as CMOS types, bottom circuit) that can pull the output to ground (red trace).
Yeah, that is my question back to the TS - How close to 0.000 V does the translated output signal have to be? Can you give us more information about what is downstream / what the output is driving?

ak

#### Ian0

Joined Aug 7, 2020
8,941
LM324 has a low current NPN transistor in parallel with a PNP on the low-side of the output. It can pull down quite close to zero, but with rather limited current (50uA). 0-10V inputs tend to have a pulldown resistor, which give it a helping hand.