I want what I hope is a simple circuit but I've googled and searched this forum, not found it.
When a SPST digital programmable timer completes a circuit, I want one motor to run. On the next circuit completion from the timer the other motor. Next time, the first motor, and so on.
I can do this with two timers, each set on different times. But I would like to know if there is a simple way to do it with one timer.
Do NOT want a circuit that must be energized all day long. Over time that increases greatly the battery and solar requirements. Something like a latching relay? A bi stable flip flop maybe?
The application: A chicken coop door. Two water reservoirs. To open, fill the bottle on the door pulley. To close, pump from the door pulley bottle to the bottom reservoir. I can use an up timer and down timer but I think this can be done with some kind of latching relay or something.
The goal is to be very low-cost and simple. If the alternative to two timers costs more than the second $5 timer, I'll go with two timers.
Best Answer
You need circuit, that has two parts:
1. H bridge to be able run motor in both directions. I will not go to details about that, Mr. Google knows all about it, just ask him.
2. "Button with memory"
You have timer, which closes circuit, just like a button. I'm a simple person, I like simple things, I will speak like it is a button.
You need different initial conditions when this button is pressed. In fact you have different conditions alredy, you just need to take advantage of it. One condition is with doors closed, the other with doors open.
I would suggest using relays to implement it. To detect initial condition, there are many possibilities, one of them is magnet and reed relay. Place magnet on the top of doors and place reed relay in position, that matches with magnet when doors are open, or closed, whichever fits you better.
You need two additional relays to remember initial condition after doors will start moving and that's it. You have signal direction signal, which you will use as input for H bridge.