Op Amp Circuit Problem

[raflyer]

Hi all,
I am having an issue with a little circuit I built utilizing a 272 op amp. The signal coming into the op amp is a -.057 to -3.57Vdc. I built this little circuit to Invert the input and scale it up a small amount. Here is the formula, -.057vdc = 1 nautical mile So i am using this op amp to scale and invert the input and it's output goes to a simple panel meter. Per the simple diagram below, RF= 15K Rin= 8.7K I also have a 1K on the non-inverting input on the gnd side. I have 15Vdc feeding the op amp single polarity pwr supply and Vin is the aforementioned -.057 to -3.5Vdc This all worked the first couple of times I used it. But one time when I shut off power to my motion system , the meter blinked and since then circuit does this. It doesn't Invert the input and it isn't scaling it up anymore. So now when the input is say -2.0Vdc the output is -.44Vdc. I hope this all makes since?? Did I take a surge through the gnd and fry the op amp? I am at a total loss. I have had this happen to 2 op amps now. What should I do? Thanks for your help

Rob

**broken link removed**

 

[ronv]

Couple of questions:
The input is a negitive .057 to a negitive 3.57? If so it won't work on a single supply.

 

[raflyer]

Couple of questions:
The input is a negitive .057 to a negitive 3.57? If so it won't work on a single supply.

Luckily I have a dual polarity power supply, +15Vdc -15Vdc so instead of Gnd Pin 4 which is the op amp gnd, i should take it the -15vdc Correct?

 

[raflyer]

Ok, I hooked up -15Vdc to pin 4 which is - side of the 272. Now my Vin = Vout. There is no amplification at all going on. I must have fried the 272 op amp??

 

[ronv]

The TLC272 is only good with up to 18 volts across it. Maybe a +/- 5 volt supply?
That one is toast.

 

[raflyer]

Thanks for the help! I am going to order an LM358 as it has a higher voltage capability on dual supply.

 

[ronv]

That should work.