How to implement a delay on power on push button?

[eidtech]

I want to know how can i implement a delay on power on push button.

So i want to power a device after push button has been pressed for 3 or more seconds.

It is like power button on cell phones and other electronics devices.

Thank you very much

 

[VVV]

Re: Delay Power On

You can use a 555 timer to implement the delay.
In the astable circuit, disconnect the DISCH pin, and make sure your button shorts the timing cap to ground when not pressed. Once you press the button, it should open its contact and the timing cycle will begin. Once the time has expired, the output will turn on and stay on until you release the button.
Is this the operation you intended?

 

[A.Anand Srinivasan]

Re: Delay Power On

maybe you can use a current source circuit whose power supply switch can be controlled by you and the output of this current source is connected to a capacitor of large value and this voltage across the capacitor connected to a comparator and you can use the comparator output to switch on your system... since the capacitor takes some time to charge to a particular voltage you can use this fact for the delay power on.....