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Author Topic: Time Delay Question  (Read 2259 times)

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nate

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Time Delay Question
« on: March 15, 2012, 06:31:39 AM »
I'm looking at a circuit to receive a signal, say a button is pushed, and after some time, hopefully this can be adjustable, the "light" turns on.

Basically I have a water sensor, and when the water is turned on, it send a signal out.

(http://www.google.com/products/catalog?q=water+flow+sensor&hl=en&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1680&bih=801&um=1&ie=UTF-8&tbm=shop&cid=14198449091299627086&sa=X&ei=iI1eT53GCsT00gHmsfWtBw&ved=0CI8BEPMCMAY4FA)

I want this to close the circuit, and after 1 to 5 hours, be able to send power to a solenoid to shut off the water.  The circuit will hopefully power a 1" solenoid.  Can this also be done with batteries, assuming they are powerful enough to close the solenoid...

kam

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Re: Time Delay Question
« Reply #1 on: March 17, 2012, 09:38:54 AM »
First solution (for those who do not know and do not want to work with PCBs and circuits): You can get a programmable timer from electric stores. These are high precision programmable on delay / off delay components which fits to your requirements excellent. They have a relay contact output and you can control high current and voltage loads easily.

Second solution (for those who do not apply to the previous solution): The delay you want to achieve is very high, and i always advice people to work with microcontroller circuits for such high delays. One made once a very nice system for irrigation, but it can work for you as well:
http://pcbheaven.com/opendir/index.php?show=7366er7836njb2059997