Volume VI - Experiments High Impedance Voltmeter
When trying this experiment I still get a reading of about 0.5V on the Voltmeter even when the test probe is not connected.
The OA I'm using is an ST MC1458N because that's what I found at the electronics shop. I was told that this is the same as the LM1458. All the other parts are OK apart that instead of the four 6V batteries I'm using a DC power supply.
I'm still very green on the subject but to me it seems like the OA is in "latch-up". The Voltage readings taken from the three test points are correct.
Please help.
Also how can I use this circuit to measure an external Voltage source?
Thank you.
When trying this experiment I still get a reading of about 0.5V on the Voltmeter even when the test probe is not connected.
The OA I'm using is an ST MC1458N because that's what I found at the electronics shop. I was told that this is the same as the LM1458. All the other parts are OK apart that instead of the four 6V batteries I'm using a DC power supply.
I'm still very green on the subject but to me it seems like the OA is in "latch-up". The Voltage readings taken from the three test points are correct.
Please help.
Also how can I use this circuit to measure an external Voltage source?
Thank you.