Electronics 2000

Greetings

I'm from the UK and would like to build an automated door control for my chicken house.
I wanted to go with a timer and not a light meter.

So what I'm having trouble finding is a cheap analogue or digital clock to give an output, high or low trip at predetermined times (one in the morning to open and one in the evening to close) it also need to be DC i.e. 9v.

There are a lot of cheap analogue mains operated timers out there, but I really cant get a main supply to the chicken house.

I hope to use the time to trigger a pic possessor or stamp to control a stepper motor.

I look forward to any replies.

Regards

Stevie P

Here is an idea inspired by an article on solar powered poultry lighting. The timer they suggest for lighting can be adapted for door closing.

http://www.reuk.co.uk/print.php?article ... ghting.htm

The timer would be set to be on for the period the door should be open. You’ll need switches to tell the controls when the door is open and when it’s shut. When the timer is ON the control circuit will run the motor to open the door until it opens the open limit switch. When the timer is OFF the control will run the motor the other direction until the closed limit switch is opened. This method will work with a simple D.C. motor.

The details of the control circuit depend on the motor you use and the available power. Two relays will likely do the trick if the timer has both a normally open and a normally closed output. If your timer only has one output, and battery drain is a not worry, an addition relay could be used to provide the normally closed output. Otherwise, a combination of relays and CMOS logic could save power.

There was a reason battery powered timers disappeared (along with public waste bins) from general use and that was their possible use by terrorists in the days when terrorists left bombs and run away and hid,rather than blew themselves up as they do today.








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