Hi, I am building horse feeders.
I want 6 food shelves. I want to program the drop mechanism to anytime like every 4 hours. Which would cover an entire days feeding.
But I want the switch to only have power for a short period of time so as Not to burn out the release mechanism. Do you have anything that might work for me? Or any ideas to help me?
Requirements: 12vdc, 6 independent relay switch positions, 24hr programmable timer, very short activation times.
I have made two so far (3 food shelf system) using: I welded a steel frame to support everything and hang on a wall and a drop chute to go to the opposite side of the wall, a 12vdc programmable switch with 3 independent switches, 12vdc battery with a 120ac charger, the food shelf is recycled street signs on spring loaded hinges.
My release mechanisms are 12vdc car door actuators. The 12vdc programmable shitch has a minimum activation of one minute, which sometimes burns out the car door actuator.
So I am looking for a 6 switch system, with a shorter activation time. or a way to break the electrical signal once the shelf drops.
I have photos of my project if anyone wants to see it.
Thanks for the help,
You can private email me to : androman@ctcweb.net
Robert

 

You could put a current limiter, or resistor of half the coil value in Series with the door solenoids, with a 1000uF cap in parallel with the limiter, so the solenoid will activate then as the cap charges up the current is limited, this will prevent burnout.

 

An all mechanical approach is to wire a microswitch operated by shelf, in series with the latch.
The microswitch NO contacts open when the shelf drops, removing the power to the latch.
Make sure there is a diode across the latch coil (cathode to positive side) to minimize arcing of the contacts.

 

How fancy do you want to get? I can give you a circuit for an electronic timer to activate 1 of 6 (or 60) relays sequentially, for a few seconds each; or you could get a geared 1 rev/day motor (they're cheap and available at 12 volts), mount a wheel with a notch and a string of micro switches around the periphery to activate the gates sequentially, and another on each gate per Crutschow... . . .