MCP4921 DAC and LM324 got damage

[dhakeparag81]

Hello Guys,

I'm using bellow attached ckt to generate 0-10v reference for VFD (variable frequency Drive) to control speed. In which MCP4921 dac is used to generate analog output and using LM324 op-amp i am able to generate 0-10v.
My problem is when drive used in close loop configuration bot the ic got damage if supply voltage to LM324 is given through drive, and i we give supply to lm324 from regulated power supply then ckt works but again got damage after some time. If we used it in open loop configuration then it works but for some cases it got damage.

Iam also new to open and close loop configuration of drive as i didn't get a chance to work with it, im attaching a link here explaining open and close loop vfd working.

Any Advice on It.
Iam thinking to use isolated OP-amp, If anyone know a better low cost op-amp (replacement), please let me know.

This ckt works great other than that, VFD is very noisy environment to work with, if someone need 0-10v ckt its good one.

 

[KlausST]

Hi

the shown circuit is not the problem.
The problem may be how it is connected to your other devices (VFD, power supply)

You need to show us the whole story.

Klaus

 

[dhakeparag81]

there is couple of things related to analog input in the pdf im pasting then here instead of attaching whole pdf.

1. Input range: 0–10V/0–20mA for AI1 voltage/current, switched by J3
2. Input impedance: 20kΩ for voltage input; 500Ω for current input
3. Resolution: 5mV as the min. resolution when 10V corresponds to 50Hz.
4. Deviation ±1%, 25˚C

input (AI1): 0–10V/0–20mA
Resolution: ≤20Mv

 

[KlausST]

Hi

I don't like to solve riddles where you connected what.

Provide compete and useful informations then I will help.

Klaus