Schmitt trigger as a delay circuit?

[shaq]

Dear all,

I need a 10ms delay time.
Is it possible to design a delay circuit by using schmitt trigger?

 

[TekUT]

You can try to use a 74HC123, just set the right R and C. As a side note take care about the manufacturer, for some the timing are R*C other 0.45*R*C.

Bye
Powermos

 

[Sadegh.j]

Hi

Use mono-stable, this is the best circuit for normal delays. check:

monostable, in which one of the states is stable, but the other is not - the circuit will flip into the unstable state for a determined period, but will eventually return to the stable state. Such a circuit is useful for creating a timing period of fixed duration in response to some external event. This circuit is also known as a one shot. A common application is in eliminating switch bounce.

You can read the rest in:

https://en.wikipedia.org/wiki/Multivibrator

Cheers

 

[ricklin]

For so long time delay, maybe a digital counter is more suitable than analog ciruits, if your system do have clock.

 

[shaq]

You can try to use a 74HC123, just set the right R and C. As a side note take care about the manufacturer, for some the timing are R*C other 0.45*R*C.

Bye
Powermos

Dear TekUT,

Because of this delay circuit is needed to design inside an IC. For t=0.45*R*C, I need a mega-ohm resistor in an IC.

Any idea on it?

 

[flyingsky]

hi,
when you get t=0.45*R*C=10ms/N,you can get the delay time just a D trigger.(N=2,4,8,---)