Dear All,
I am making a circuit which compares the ferrite insulation resistance.
Working/ Aim of the circuit:
Using comparator I am comparing the voltages of divider network. If resistor R7 is more than 100Mohm then the test is pass. A green LED will glow.
If R7 is less then 10Mohm, the test will fail and RED LED will glow.
IF R7 is not connected to the test-point, then ORANGE LED will glow.
Actually R7 is a resistance of a ferrite. I am developing this circuit to compare the ferrite insulation resistance.
Attached schematic I snipped from LTspice, where I tried simulations. We can see voltages available at different nodes.
Please see the attached schematics.
First schematic : Comparator with test point resistor (R7) connected.
Second schematic : Comparator with test point resistor (R7) not - connected.
Issue
Problem is with the circuit when I remove the R7 resistor.
Both GREEN and ORANGE LED become ON. I only want ORANGE to be glow.
I know when I remove the R7 the resistance, at that node resistance become infinity so, the GREEN LED will glow.
For R7 open condition I just want to glow ORANGE LED.
Please guide and suggest changes in schematic .
Thanks.
I am making a circuit which compares the ferrite insulation resistance.
Working/ Aim of the circuit:
Using comparator I am comparing the voltages of divider network. If resistor R7 is more than 100Mohm then the test is pass. A green LED will glow.
If R7 is less then 10Mohm, the test will fail and RED LED will glow.
IF R7 is not connected to the test-point, then ORANGE LED will glow.
Actually R7 is a resistance of a ferrite. I am developing this circuit to compare the ferrite insulation resistance.
Attached schematic I snipped from LTspice, where I tried simulations. We can see voltages available at different nodes.
Please see the attached schematics.
First schematic : Comparator with test point resistor (R7) connected.
Second schematic : Comparator with test point resistor (R7) not - connected.
Issue
Problem is with the circuit when I remove the R7 resistor.
Both GREEN and ORANGE LED become ON. I only want ORANGE to be glow.
I know when I remove the R7 the resistance, at that node resistance become infinity so, the GREEN LED will glow.
For R7 open condition I just want to glow ORANGE LED.
Please guide and suggest changes in schematic .
Thanks.