Window comparator using single 555 ?

[Externet]

Hi.

If I understand well, a 555 chip is a window comparator by itself, the window being 1/3 to 2/3 Vcc.

Can the window be tailored to yield output between 2.9 and 3.1 Volts ? [the Vcc supply is +5V]

 

[blueroomelectronics]

Why not just use a dual comparator?

 

[kchriste]

Can the window be tailored to yield output between 2.9 and 3.1 Volts ? [the Vcc supply is +5V]

No, because you can only get at one of the junctions of the resistive divider via pin5. Therefore, the upper window voltage will always be double that of the lower one.
EDIT: I guess you could do something like this with a 555, but it's not very elegant:

 

[Externet]

Thanks, fellows.
The circuit works perfect with a LM393, but needed to duplicate and ran out of those chips . Tried LF353 on hand; does not work. Will have to wait until more come in.
Miguel