NE555 Delayed ON

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Suraj143

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When I apply power i need the LED to be wait 10 sec & turn ON.Below circuit the LED is always on??

 
eTech said:
Connect the anode of LED to +9v and cathode to R3, so that when the timer is triggered the LED is OFF until the time expires.
Also connect pin 7 to pin 6.
Click to expand...
If you leave the DIScharge pin disconnected, then you can tie THRES and /TRIG together and only use one RC pair.
 
Suraj143 said:
Can you tell me is my circuit ok? Then why on the simulator won't work
Click to expand...
Interchange the position of R1 and C2 so the TR and Th are low, not high, when power is applied.
TR triggers the 555 when it is low.

LTspice simulation below:
D1 is to rapidly discharge C1 when power is removed, if you need a rapid reset for the next sequence.

 
Last edited:
Many thanks.I swaped the R and C in my 1st drawing.

When giving power from 5V it is working nicely.When I feed the circuit from a 12V supply the LED never gets off.

Note: I need when power ON led MUST ON.It should OFF after the delay.I have fixed the LEDs possitive to the Pin 3 and negative to the Ground.

Why the LED never gets off when feeding from a 12V source?
 
Suraj143 said:
Why the LED never gets off when feeding from a 12V source?
Click to expand...
Is the complete circuit powered from 12V?

The LED needs to go to V+ as eTech's and my circuit shows.

Is this a simulation or a real circuit?
 
crutschow said:
Is the complete circuit powered from 12V?

The LED needs to go to V+ as eTech's and my circuit shows.

Is this a simulation or a real circuit?
Click to expand...
The Whole circuit powered from a 12V source.Still my LED is other way not as your one.I will change that as well.

Finally I want to drive a 12V relay. I think I can direct connect the relay to the IC.
 
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