comparator dead zone

[Joe G]

i've been playing around with comparators lately learning how they work. but my question is, is there a way to make them have a dead zone instead of being either sourcing or sinking, i've looked for a while and can't figure out if it is possable.

 

[Reloadron]

You can have high or you can have low but there is no in the middle.

You can apply hysteresis to keep them from bouncing but I don't know of a tri state comparator. That does not mean one does not exist only that I am not familiar with it if it does.

Ron

 

[Joe G]

yep, thats what i thought also., thanx

 

[Mikebits]

Some comparators have a output enable pin, which basically puts the output into a tri-state condition. If that is what you are looking for?
https://www.electro-tech-online.com/custompdfs/2010/09/tl712.pdf

 

[Joe G]

i was working on a linefollowing bot but i wanted it to have frt wheel steering. i finished it on a breadboard. but i was trying to eleminate a relay. i didnt want it to zigzag,. but stay on the same direction untill the sensors changed it. and i tryed to figure out if there was a way to make a comparator do that

 

[Joe G]

but, yea , i think that would work. thanks

 

[Reloadron]

Some comparators have a output enable pin, which basically puts the output into a tri-state condition. If that is what you are looking for?
https://www.electro-tech-online.com/custompdfs/2010/09/tl712-1.pdf

Thanks Mike, interesting. I was thinking about using an added chip for the effect but that chip using an enable seems the ticket.

Ron

 

[peufeu]

> is there a way to make them have a dead zone

It's called a window comparator, you make that with 2 comparators. It has 3 outputs : above window, below window, inside window.

 

[Reloadron]

> is there a way to make them have a dead zone

It's called a window comparator, you make that with 2 comparators. It has 3 outputs : above window, below window, inside window.

Yeah, but you still only have 2 states correct? Above or below are a state just like in the window is a state.

Ron

 

[Grossel]

Joe G

I have make up a sketch of a voltage follower. But I have added a small grid of bjt's around it to make it possible for it's output impedance to become high.
I haven't been able to test it on a bread board, but if you're interested of testing the concept, I can draw it. But then you must agree to post a detailed report back on this forum.

 

[Joe G]

i think ive figured out a way to do want to accomplish, but haven't been to the breadboard as of yet, if it works, i can finish construction and make a new post of my outcome

 

[Boncuk]

Hi Joe,

you might look at this design.

It's a 3 point floating comparator, used for a solar tracker.

Boncuk

 

[Joe G]

is the solartracker circuit for use w/ a controler? cause i'm not able to use them as of yet

 

[Boncuk]

is the solartracker circuit for use w/ a controler? cause i'm not able to use them as of yet

The solar solar tracker is a stand alone circuit working without microprocessor. Just take a look at the OpAmps and the circuitry after them which control two motors via miniature relays (forward and reverse).

Boncuk