DAC with simulator

[can1232423534657457]

Hello everyone, I want to create a circuit that can simulate the output signal of an LVDT sensor. Since this will be a sensor simulator, the accuracy of the data in the system is very important. I was thinking of achieving this by processing a sine wave signal with the AD5453 integrated circuit. Do you think this is possible, and how can I make this?

 

[BradtheRad]

Articles tell about AD5453 as a D-to-A converter, not A-to-D. Does your LVDT sensor produce analog output (sine wave)?

 

[can1232423534657457]

Yes, the output signal of the LVDT sensor will be an analog sine wave between sine+ and sine-, with a fixed frequency and varying amplitude. @BradtheRad When I only adjust the voltage, it will appear as if the position is changing, and I want the output signal to change according to this position change."

 

[BradtheRad]

To simulate the output of a transducer....
This seems like you wish to build a sine wave generator. Bipolar AC at a few mA? There are several types of circuits which do this.

A DAC chip (like AD5453) needs to be fed specific data figures at a specific speed, which may require effort to achieve.

Can you read the sinewave using a normal digital multi-meter? There's a question whether the sine wave can be described as:
* AC (mains frequency) or,
* resembling slow AC which can be read on DC range twice per second or seldom.

 

[can1232423534657457]

Yes, I agree, as you said. I will take the signal from the AC signal generator. I want to see a waveform like (+,-)10V at the output. I will provide the reference voltage to the DAC via the microprocessor." But I can't desing that ?

 

[FvM]

You can use datasheet Fig. 45, 4-quadrant mode circuit. Reference sine should be scaled to +/- 10 V.

 

[BradtheRad]

I will provide the reference voltage to the DAC via the microprocessor."

A microprocessor usually runs on +5V supply. With some effort you can obtain a waveform from it whose voltage is between 0 and 5V.

To get +10V-10V you could use an opamp circuit (powered by a bipolar +10-10V supply).

To include a DAC you need something like a dozen wires carrying 1's and 0's into the DAC. Those 1's and 0's have to be generated from a chip/chips supporting that many wires. I'm not sure you wish to go to that amount of effort.

 

[mtwieg]

If your goal is to create something that can be used in place of a real LVDT, a multiplying DAC such as the AD5453 seems like a good option. See figure 45 in the datasheet. Vref is the "primary" and Vout is the "secondary". Depending driver/receiver circuitry for the LVDT, you may need to use isolation transformers on one or both sides.

If the LVDT interface requires a five-wire LVDT (connected to the center-tap of the secondary), you may need to get a little more complex in order to produce two sinewaves with complementary amplitude. Likely could be done by adding an additional difference or summing amplifier to figure 45.

Hard to say more without knowing more about the application. Resolution and drift might be an issue. Could probably just pay more for better specs (LTC2752 comes to mind).

 

[KlausST]

Hi,

two basic questions:
* what has all this to do with "power electronics"
* are you sure you want "simulation"? .. or maybe "emulation"?

Klaus

 

[FvM]

Yes, thread better fits analog circuit design forum. And intended function is commonly named sensor emulator, but I don't see a risk of misunderstanding.

 

[KlausST]

but I don't see a risk of misunderstanding.

My first thought was to use it in a simulation software ... but I also had my doubts.

Klaus

 

[FvM]

O.k., may be not clear enough, but reference to multiplying DAC AD5453 is a strong hint.