Voltage Level Switch

[Supercap2F]

Oh, I get it now!




Regards

Dan

 

[Arouse1973]

Correct

 

[Supercap2F]

What would I use for the U1 voltage regulator.

U1 is just the power connections for the comparator.

I'm going to power the circuit from a garden tractor, probably 13-15 vdc when running.

I thought you wanted to power it off of 12VDC. You will need a voltage regulator if you want to power it off of 13-15VDC.

Regards

Dan

 

[(*steve*)]

This is what I meant:



Sorry, R1 and R2 are labelled backwards as compared to your circuit.

Note that depending on the comparator (and especially if you're using an op-amp as a comparator), the input voltage range may not extend to the negative rail. In the case of the one shown above (the TLC3702) it does.

 

[BobK]

And, once again, is the 12V regulated? If not you need a voltage reference.

Bob

 

[Supercap2F]

All right here's the updated schematic (again).



Hows it look?

Dan

 

[Gryd3]

Having a regulated 12V source would allow this to be more stable... and would prevent the alarm from triggering on a false positive from the 12V source drifting. This of course will depend on what kind of accuracy the OP wants.

Alternatively, does anyone have any objections to using a diode on the + side of that Comparator?
+12V----\/\/\/\----+---->|----GND
You would need to feed the output from the Aneamoter to a voltage divider, but that would ensure a more stable reference voltage would it not?

 

[Dan Paulovich]

All right here's the updated schematic (again).

View attachment 14181

Hows it look?

Dan

Alright, looks good I'll breadboard this and play around with it. I still have to put together a 12 vdc voltage regulator, maybe an LM7812. Thanks again Dan and everybody else you all have been really helpful.

Dan P