10 second timer.

[yafch]

hi.
i need a circuit diagram of 10 second timer with following sequence of operation.

1. 6v/9v/12v operation.
2. should turn on a relay for 10 seconds at power up, after 10 seconds the relay should turned off. In the mean time if a switch associated with the circuit is closed the relay should remain on even 10 second time is over.
Any links or diagram is much appriciated.

I have knowledge of making simple timers and repeater timers. But i dont know how to bypass the relay with a switch in a proper way.

 

[colin55]

If the switch is pressed after 12 seconds, what happens?

 

[yafch]

I can use either of two options. if the switch is closed after preset time the relay should turn on again. Second option will be better, if the switch is pressed after preset time the relay should remain off until the unit get power cycle.

 

[colin55]

Which do you want?

 

[yafch]

I prefer second one for the time being.

 

[colin55]

Here is a circuit:
**broken link removed**

 

[Grossel]

Hi Colin.

Is that one retrigable? If delay for this circuit is 10 seconds, what happens if button is pressed once again after 5 seconds? Will the new total delay time expand to 15 seconds, or will it remains 10 secs?

 

[yafch]

actually i was hoping a better design than this.