Small timer

[Niellles]

Hello everybody,

I would like to construct a small electronic timer with a delay of 5 minutes.
It should have a 9V or 12V input. (input = output in this case)

I changed my physic classes for economics last year so it is kind of a problem for me.

I tried to find how to's on the internet, but didn't find a clear solution.

Would it also be possible to change the delay (I read something about different resitors...)

I know how to solder, I only need a scheme or something like that.

Any help/suggestions are greatly appreciated!

Cheers,
Niellles

 

[Hero999]

The simplest way is to use the 555 timer.

C = 330µF

R = 1M variable resistor and 470k in series.

The delay will be adjustable and won't be very accurate or consistent: it'll vary by a few seconds each time.

**broken link removed**
Google Image Result for https://www.m0ukd.com/Calculators/555_timer_calculator/555astable.gif

 

[Niellles]

Do I get a 5+ minutes delay with this circuit?
https://www.aaroncake.net/circuits/relaytim2.asp would this be any good?

 

[Hero999]

I just told you, did you not read my previous post?

That circuit needs a transistor to boost the output and I there might be other things wrong too but it's too poorly drawn to make sense - I hate it when people just draw logic ICs as boxes without the internal gates.

 

[Niellles]

I did read your post , but does it work for a delay of 5 minutes or more?
What do you mean with the R? :$
Is it a variabele resistor next to a 470K resistor (in serie), sorry never worked with variabele resistors

 

[Hero999]

It's not the best solution for a 5 minute delay but it should work.

The resistor in the schematic should be replaced with a 1M variable resistor and a 470k resistor connected in series. If you don't know what this means, Google series circuits.

 

[Niellles]

I know what series is , was just wondering if it was indeed a 1M and an another one next to each other!
Thanks, will try this one