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Hi
THE PROBLEM
Because the input signal changes very slowly, when its at the threshold point of the opamp (against the Ref Voltage) it start to form a "square Wave" output and causing the relay to "vibrate", and not acting as a "clean" switch.
Attched is a basic schematic of the comparator and relay driver.
Thanks in advance.
hi,
Look at this mod to your circuit.
Try a 100K feedback.
The diode is to protect the transistor.
inputs are from the opamps, which are configured as "schmitt triggers" if I understand correctly.
Output will drive a 12V relay.
supply will be + - 15V. originally used the resistors as a voltage divider to drive a transistor, but would like it to drive a logic gate dirrectly.
basically what i'm wanting to do is outputs from the opamps into the Logic IC (AND) to drive a relay. so both ouputs from the opamps must be high to turn on the relay.
I know that you want to level shift the Comp outputs to logic levels, just use the circuit I posted with a resistor in each diode input.
Both inputs will have to be high in order to switch the relay.
Do you follow OK.?
EDIT:
Look at this image.