Hi!

I need a circuit that when activate from a button it is on for about 30 sec.
I've tried whit a 555 timer but the problem is that it constantly draws a current of 4mA even if it isn't in use.

How could i solve this problem?

 

what 555 are you using and how low do you want to go in the no use consumption?

 

Hi,
The TLC555 is a very low power replacement for the regular 555 timer.
It does not source or sink as much current though.

__________________
I know I learned everything at least once,
now where did I write it down?

 

I'm using a NE555N. And as low as possible..

 

put a MOSFET in series with your load
put your momentary from the power to gate
add a cap from gate to ground
the momentary will charge the cap & gate turning the MOSFET on
the size of the cap will determine how long the gate stays on,
then the charge leaks away and the circuit turns off