LM358 Question

[joe_1]

I just hooked LM358 Op Amp, and I not getting the voltage I am expected at the output.
It is connected as follows:
-The supply voltage is 5V
-There is 330 Ohm between 5VDC and the inverting input.
-There is negative feedback resistor of 1K (between inverting input and output)
-The noninverting input is ground.
-The LM358 does not have/need negative supply.

Now, simple Ohms law tells me:
The current through the 330 is 5/330 = .015A
So, the current through 1K = -.015A
The output should be Vout = (-.015) * 1000 = -15VDC
But when I measure it, it is equal to 0.816VDC
I can't figure out why. Shouldn't it be around 5VDC (the maximum it could go)
This LM358 is brand new.

Thanks.

 

[chemelec]

I just hooked LM358 Op Amp, and I not getting the voltage I am expected at the output.
It is connected as follows:
-The supply voltage is 5V
-There is 330 Ohm between 5VDC and the inverting input.
-There is negative feedback resistor of 1K (between inverting input and output)
-The noninverting input is ground.
-The LM358 does not have/need negative supply.

Now, simple Ohms law tells me:
The current through the 330 is 5/330 = .015A
So, the current through 1K = -.015A
The output should be Vout = (-.015) * 1000 = -15VDC
But when I measure it, it is equal to 0.816VDC
I can't figure out why. Shouldn't it be around 5VDC (the maximum it could go)
This LM358 is brand new.

Thanks.

I Think you better Study Up on Op-Amps and Applications.
Check out some Basic Circuits.
**broken link removed**

Op-Amps are Not Voltage Multipliers to get 3X out of Supply Voltage.
Maximum Output Swing on your Circuit will be about 4.4 Volts with a 5 Volt Supply.
Presently you have basically Unity Gain, But you need an Input Signal to get an output.

For a Gain of 3, Not Just a Feedback Resistor, Also Another Resistor to Input.

 

[audioguru]

How can there be 15mA in the 330 ohm and 1k resistors in series??
5V/1300 ohms= 3.85mA. But the output is not at ground (it cannot be negative without a negative supply), it is +0.05V so the current in the resistors is 4.95V/1300 ohms= 3.81mA.
The output voltage cannot go higher than the 5V supply voltage minus 1.2V= 3.8V.