Hello all

Any one know the best way to do this.

I need to be able to push a switch, and turn on a light for 3min and then have it turn off automaticly.

It needs to fit within a 1 inch square and be water tight.

Does anyone know any other way to do this?

Robert

 

Can you provide more information on the application of this pushbutton watertight light source?

At what depth does this device need to operate?

hgmjr

 

Find a timer relay with the specifications you need. I think you can find something like that.

Uses a timing resistor, It's too big though.
http://rocky.digikey.com/WebLib/Crydom/Web Data/DSD, DLD Series.pdf

Without your specs can't go further.

 

Well I am not sure what you need,

I will be powering a 25 LEDs from a verysmall 12v battery [1/2 size of a AAA] it will use a tilt switch and when activated... the light will turn on for 3 min and then turn off automaticly... regardless if the switch is turned off or not.

It will be in a wet area not submerged, it needs to fit into a 1" square or as small as poss. Solid State would be best i think if there is such a thing.

Hope that is what yyou need

 

A U6046 or U6047 8 pin dil IC designed for automotive applications such as heated screen timing can produce time delays of 3.7 sec to 20 hours, designed for 12v operation and can switch 300mA. Only problem may be the 1.3mA typical supply current if running from batteries.

When switched on by an 'on' contact it will switch off by either an 'off' contact or when the time delay expires - needs 3 resistors + 2 capacitors so should be within your size constraints..

Datasheet available at:-

http://pdf1.alldatasheet.com/datasheet-pdf/view/90384/TEMIC/U6047B.html

Steve.