Hello Guys....
I have this Latch Circuit as attached below...
I want to make this Latch after a DELAY. Is it possible?
When powered on, The Relay Activates. What I need is, When you press the push button, The Relay should release after a DELAY which can be set using a Potentiometer. How can I do this?

Thank you.




PS: It doesn't matter if the initial state of the Relay is NORMALLY OPEN. Its just how this circuit works. Its totally ok to suggest a new circuit where the relay is not connected at the initial state, and the push button connects the relay after a delay.

 

I can't think of a way to do that without using two 555's or one 556.
Would that be okay?

How do you want to reset the circuit?

 

I can't think of a way to do that without using two 555's or one 556.
Would that be okay?

How do you want to reset the circuit?

There is no need for a Reset unless the power is restarted?

And if its impossible... I guess its ok to use 2 ICs or a 556...

 

I believe pin 3 changes state after a delay from the trigger. If the relay has its other pin to + instead of gnd, it would make a difference. Remember reading somewhere, looong ago, how to modify the 555 circuit so it does not activate at power-on.

 

What is the voltage and current (resistance) rating of the relay coil?

 

Just a standard 5V 10A Relay

 

Here's an ON delay circuit using two 555s (or one 556).
The first 555 generates a one-shot pulse width of ≈ R2C1.
The second 555 is configured as a latch that turns on at the end (trailing edge) of the first 555 pulse.
I added a MOSFET buffer to drive the relay as the output current of the 555 is somewhat marginal to directly drive the relay load.
If you prefer you could use a BJT transistor, such as a 2N2222 with a 390Ω base resistor, in place of the MOSFET.

 

Here's a delay-on circuit using one CD4013 Flip-flop package, which requires only about half the parts of the 555 circuit.
The delay is approximately 0.7 R5C4.
Turning the power off resets the circuit output to zero.

 

Hello, I am trying to solve a problem using a 555 and I came across this page.
I would very much appreciate if you could have a look at my question.
And also, I would like to run a simulation, seems like your program does that, can you please let me know which program are you using for the simulations ?

Thank you

 

an you please let me know which program are you using for the simulations ?

LTspice and it's free.

https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html

If you're just learning, you'd be better off doing things manually so you'll learn more. Using a simulator before you can design is akin to using a calculator before you learn how to do arithmetic; you'll never learn and will be helpless without an aid.

 

Thank you for your help